Central Price Management

The Challenge

Anyone selling on multiple marketplaces and sourcing goods from various suppliers faces a complex pricing question:

Each supplier has their own purchase prices that change regularly
Different suppliers offer the same item at different conditions
Each supplier has their own ancillary costs (shipping, insurance, discounts)
Each marketplace has its own fee structures (commissions, shipping costs)
Each channel needs its own sales prices with marketplace-specific margins
Prices must be recalculated immediately when the purchase price changes
The MSRP (Manufacturer's Suggested Retail Price) must not be exceeded
Safety mechanisms must prevent extreme price jumps

Manually managing this for hundreds or thousands of items is no longer feasible.

The Idea Behind the Price Engine

The merchantCENTRAL Price Engine is an optional calculation module that automates the entire path from supplier purchase price to the final marketplace sales price. It follows three core principles:

Best Supplier Wins: If multiple suppliers offer the same item, the lowest net price is automatically determined, taking all ancillary costs into account.
Flexible Margin Configuration: Margins can be defined at various levels – global, per price list, per item category, per supplier, or even per individual item. The most specific configuration wins.
Full Transparency: Every single price calculation is logged in the calculation log. You can always trace why a specific price was determined.

The Price Engine is not a mandatory module – without it, the hub works with manually maintained prices. Once installed, it automatically takes over calculations via events, without modifying existing logic.

The 11-Step Pipeline Overview

Each price calculation passes through a structured pipeline with 11 steps:

Step 1: Find Best Offer

When multiple suppliers offer the same item, the Price Engine searches for the lowest net price from the Supplier Data Pool. Two optional filters are considered:

Supplier Filter: Only consider specific suppliers (e.g., 20200|21002|70030)
Stock Required: Only include suppliers with available stock

Example: Supplier Selection

A scanner is offered by three suppliers:

Supplier	Net Price	Stock
Jarltech (20200)	€185.00	12 pcs
BlueStar (70215)	€192.50	8 pcs
Systeam (21002)	€178.00	0 pcs

Without "Stock Required": Systeam at €178.00 wins. With "Stock Required": Jarltech at €185.00 wins (Systeam has no stock).

Step 2: Calculate Purchase Price (Supplier Cost Conditions)

The raw net price from the supplier is rarely the actual purchase cost. Suppliers have different conditions: shipping costs, insurance surcharges, and possible discounts. The Supplier Cost Setup table maps these conditions.

Calculation Formula

$$ \text{Purchase Price} = \text{Net} \times (1 - \frac{\text{Discount\%}}{100}) + \text{Shipping}^* + \text{Net} \times \frac{\text{Insurance\%}}{100} $$

Shipping costs are only added if the discounted price is below the minimum order value for free shipping.

Example: Purchase Price Calculation

Supplier Jarltech, item category "POS Systems":

Net price: €185.00
Discount: 5%
Shipping: €6.90
Free shipping threshold: €250.00
Insurance: 0.5%

Step by step:

Apply discount: 185.00 × (1 − 0.05) = €175.75
Shipping: 175.75 < 250.00 → Shipping + €6.90
Insurance: 185.00 × 0.005 = + €0.93
Purchase Price = 175.75 + 6.90 + 0.93 = €183.58

Example: Free Shipping (above threshold)

Supplier BlueStar, item category "Printers":

Net price: €520.00
Discount: 3%
Shipping: €12.50
Free shipping threshold: €500.00
Insurance: 0%

Calculation:

Discount: 520.00 × (1 − 0.03) = €504.40
Shipping: 504.40 ≥ 500.00 → no shipping (free shipping)
Insurance: 0%
Purchase Price = €504.40

Supplier cost conditions can be configured per supplier and per item category. For example, supplier X can have different shipping costs for printers than for accessories.

→ Detailed setup: Supplier Costs

Step 3: Determine Margin (Hierarchical Search)

The Price Engine uses a four-level margin hierarchy. The most specific configuration always wins:

Level 1: Price List + Category + Supplier + Item   (most specific)
    ↓ not found?
Level 2: Price List + Category + Supplier
    ↓ not found?
Level 3: Price List + Category
    ↓ not found?
Level 4: Default margin from Price Calc Setup       (fallback)

Example: Hierarchy in Practice

Setup (Price Calc Setup for price list "SHOP"):

Default margin: 25%, Rounding: Round99

Category Margins:

Price List	Category	Supplier	Item	Margin %	Rounding
SHOP	POS			20%	Round99
SHOP	POS	20200		18%	Round90
SHOP	POS	20200	SCANNER-X1	15%	None
SHOP	ACCESSORIES			30%	Round99

Hierarchy result:

Item SCANNER-X1, Supplier 20200, Category POS → 15%, None (Level 1)
Any POS item, Supplier 20200 → 18%, Round90 (Level 2)
Any POS item, any supplier → 20%, Round99 (Level 3)
Item from category "SOFTWARE" (no match) → 25%, Round99 (Level 4, Fallback)

→ Detailed setup: Category Margins

Step 4: Apply Margin (Divisive Margin Calculation)

The Price Engine uses a divisive margin formula (not markup-based). The difference is important:

$$ \text{Sales Price} = \frac{\text{Purchase Price}}{1 - \frac{\text{Margin\%}}{100}} $$

Why Divisive Margin?

With a markup-based calculation (PP × 1.25), the actual margin on the sales price is only 20%. The divisive method ensures that the configured margin exactly represents the share of the sales price.

Method	Formula	PP = €100, Margin 25%	Actual Margin
Markup (multiplicative)	100 × 1.25	€125.00	20% of SP
Divisive (Price Engine)	100 / (1 − 0.25)	€133.33	25% of SP

Safety Net: Minimum Amount and Minimum Margin

Two mechanisms prevent cheap items from being sold with too low an absolute margin:

Minimum Amount (Min. Margin Amount): If the percentage margin yields less than the minimum amount, the minimum amount is used as the markup.

Example: Minimum Amount Applies

PP: €10.00
Margin: 20% → normal SP = 10 / 0.8 = €12.50 → Margin = €2.50
Minimum Amount: €5.00
€2.50 < €5.00 → SP = 10.00 + 5.00 = €15.00

Minimum Margin % (Min. Margin %): A percentage floor that must not be undercut – not even by category margins.

Example: Minimum Margin Applies

PP: €200.00
Category Margin: 8% → SP = 200 / 0.92 = €217.39
Minimum Margin in Setup: 12%
8% < 12% → SP = 200 / 0.88 = €227.27

Steps 5–6: Marketplace Adjustments (Events)

After the base price calculation, the pipeline offers two event interfaces through which marketplace connectors can make their own adjustments:

Step	Event	Example
5	`OnAfterCalculateBasePrice`	Connector adjusts base price (e.g., currency conversion)
6	`OnApplyMarketplaceFees`	Amazon FBA fees, Conrad commissions, etc. are added

These events allow, for example, an Amazon price list to factor in different fees than an Otto price list – without modifying the Price Engine itself.

Step 7: Rounding Rules

The calculated price is rounded according to a configurable method. Rounding can be defined globally in the setup or per category margin.

Rounding Method	Description	Examples
None	No rounding, price stays as calculated	€133.33 → €133.33
Round99	Round down to nearest amount ending in .99	€133.33 → €132.99, €45.01 → €45.99, €100.00 → €100.99
Round90	Round down to nearest amount ending in .90	€133.33 → €132.90
Round95	Round down to nearest amount ending in .95	€133.33 → €132.95
Commercial	Standard commercial rounding to 2 decimals	€133.335 → €133.34, €133.334 → €133.33

When to Use Which Rounding?

Round99: Most common in B2C – prices like €49.99 or €132.99 appear cheaper.
Round90/Round95: For marketplaces with strict pricing requirements.
Commercial: For B2B price lists where psychological pricing doesn't matter.
None: When a downstream system handles the rounding.

Step 8: MSRP as Price Ceiling

The Price Engine optionally checks whether the calculated sales price exceeds the lowest list price (MSRP) of all suppliers for this item. If so, the price is capped at the MSRP.

$$ \text{Final Price} = \min(\text{Calculated SP}, \text{lowest MSRP of all suppliers}) $$

Why Is This Important?

Many marketplaces (Amazon, Kaufland, Otto) monitor MSRP compliance. Products offered above MSRP can lead to:

Listing blocks on the marketplace
Warnings from brand owners
Lower rankings in search results

Automatic MSRP capping prevents these issues.

Example: MSRP Capping

A thermal printer is offered by two suppliers:

Supplier	Net Price	MSRP (List Price)
Jarltech	€180.00	€299.00
Toshiba	€175.00	€279.00

Calculation (Margin 25%, Round99):

Best PP (after costs): €175.00 (Toshiba)
Margin: 175 / (1 − 0.25) = €233.33
Rounding: €232.99
Lowest MSRP: min(299, 279) = €279.00
232.99 < 279.00 → no cap needed
Final Price: €232.99

If the calculation had yielded e.g. €295.00, the price would be capped at €279.00.

Step 9: Competitor Adjustment (Event)

Via the event OnApplyCompetitorAdjustment, marketplace connectors can adjust the price within an allowed range – e.g., for repricing logic on Amazon, where the price is adjusted to match the competition.

Step 10: Safety Checks

Before the calculated price is saved, it goes through three safety checks. If any check fails, the price is rejected and the previous price is retained:

Check	Setup Field	Description
Minimum Price	Min. Price	The sales price must not fall below this amount
Maximum Price Change	Safety Max Change %	The price change from the previous price must not exceed this percentage
Minimum Markup	Safety Min Markup %	The markup on the purchase price must be at least this percentage

Example: Safety Check – Maximum Change

Current SP: €150.00
New calculated SP: €90.00
Safety Max Change %: 30%
Price change: (150 − 90) / 150 = 40%
40% > 30% → Price is rejected (Result: Rejected)
Log entry: "Price change 40.00% exceeds safety limit 30.00%"

This prevents a faulty supplier import (e.g., a price accidentally imported without a decimal point) from immediately destroying all marketplace prices.

Example: Safety Check – Minimum Markup

PP: €100.00
Calculated SP: €103.00
Safety Min Markup %: 5%
Markup: (103 − 100) / 100 = 3%
3% < 5% → Price is rejected

Step 11: External Validation (Event)

The event OnValidateCalculatedPrice allows external apps to check or log the price before saving.

Complete Calculation Example

Here is an end-to-end example with all relevant steps:

Complete Example: Barcode Scanner SG-100

Starting data:

Item: SG-100 (Barcode Scanner)
Item Category: POS Systems
Price List: SHOP

Supplier data (Supplier Data Pool):

Supplier	Net Price	List Price (MSRP)	Stock
Jarltech (20200)	€85.00	€159.00	25 pcs
BlueStar (70215)	€89.50	€159.00	14 pcs
Wave (21002)	€82.00	€149.00	0 pcs

Configuration:

Stock Required: Yes
Supplier Costs Jarltech/POS: Discount 3%, Shipping €5.90, Threshold €200, Insurance 0.5%
Category Margin SHOP/POS: 22%, Min. Amount €8.00, Rounding Round99
MSRP Maximum: Yes
Safety Max Change %: 25%
Current SP: €119.99

Step 1 – Best Offer: Wave has no stock → excluded. Jarltech (€85.00) < BlueStar (€89.50) → Jarltech wins.

Step 2 – Calculate Purchase Price:

Discount: 85.00 × (1 − 0.03) = €82.45
Shipping: 82.45 < 200.00 → + €5.90
Insurance: 85.00 × 0.005 = + €0.43
Purchase Price = 82.45 + 5.90 + 0.43 = €88.78

Step 3 – Determine Margin: Search: SHOP + POS + 20200 + SG-100 → not found Search: SHOP + POS + 20200 → not found Search: SHOP + POS → found: 22%, Min. €8.00, Round99

Step 4 – Apply Margin:

SP = 88.78 / (1 − 0.22) = 88.78 / 0.78 = €113.82
Margin = 113.82 − 88.78 = €25.04
25.04 > 8.00 (Minimum Amount) → OK, no adjustment

Step 7 – Rounding (Round99):

113.82 → €112.99

Step 8 – MSRP Maximum:

Lowest MSRP: min(159.00, 159.00, 149.00) = €149.00
112.99 < 149.00 → no cap needed

Step 10 – Safety Check:

Price change: |119.99 − 112.99| / 119.99 = 5.83%
5.83% < 25% → OK

Result: ✅ Final Price = €112.99

Log entry:

Field	Value
Item No.	SG-100
Vendor No.	20200
Net Price	85.00
Purchase Price	88.78
Sales Price	112.99
Margin %	22.00
Margin Amount	24.21
Rounding	Round99
List Price Cap	No
Previous Price	119.99
Price Change %	-5.83
Result	Success

Automatic Recalculation

The Price Engine reacts automatically to changes in the Supplier Data Pool. When a supplier import delivers new prices, the entire pipeline runs for each affected item:

Automatic Supplier Import (e.g., Jarltech CSV)
        │
        ▼
  Supplier Data Pool
  (New net price from €85.00 → €92.00 detected)
        │
        ▼  Event: OnAfterInsertSupplierData (PriceChanged = true)
        │
  Price Engine
        │
        ├── 1. Re-determine best offer
        │      (possibly a different supplier is now cheapest)
        │
        ├── 2. Calculate purchase price (with ancillary costs)
        │
        ├── 3. Update purchase price list
        │      (BC Purchase Price List, with date history)
        │
        ├── 4. Calculate sales price
        │      (Margin + Rounding + MSRP Check + Safety)
        │
        └── 5. Update sales price list
               (BC Sales Price List)
                │
                ▼
        Marketplace Item: Set Price Update Flag
                │
                ▼
        Connector synchronizes new price to marketplace

The entire process is fully automatic – from supplier import to marketplace price update. No manual intervention is required.

Manual Recalculation

In addition to automatic calculation, you can trigger a manual recalculation via the Price Calculation Setup page:

For one price list: Action "Recalculate Prices" on the selected setup record
For all price lists: Action "Calculate All Price Lists"
For a single item: Via BatchRecalculation with an item filter

BC Price List Integration

The Price Engine uses native BC price lists (Sales Price List / Purchase Price List) and creates them automatically:

Purchase Price List

A separate price list is maintained per supplier
Contains the net purchase prices of all items from that supplier
Updated with each supplier import
Date-based historization: When a price changes, the old line is closed with an end date and a new line is created with the current date – so previous prices remain traceable

Sales Price List

A separate price list is maintained per configuration (e.g., SHOP, AMAZON-B2B)
Automatically calculated from PP + Margin + Rounding + MSRP
Marketplace connectors read the current sales price from this price list
Uses a Customer Price Group for assignment

Multiple Price Lists / Sales Channels

A common scenario: You sell the same item on multiple channels with different margins. The Price Engine supports this through separate Price Calc Setups:

Example: Different Channels

Price List	Description	Margin	Rounding	MSRP Max
SHOP	Own Webshop	20%	Round99	Yes
AMAZON-B2C	Amazon B2C	28%	Round99	Yes
OTTO	Otto Market	25%	Round90	Yes
B2B-DIRECT	Direct B2B Sales	12%	Commercial	No

For item SG-100 (PP €88.78) the results would be:

Channel	Calculation	Rounded	Final Price
SHOP	88.78 / 0.80 = 110.98	110.99	€110.99
AMAZON-B2C	88.78 / 0.72 = 123.31	122.99	€122.99
OTTO	88.78 / 0.75 = 118.37	117.90	€117.90
B2B-DIRECT	88.78 / 0.88 = 100.89	100.89	€100.89

Fixed Prices

For individual items, you can override the automatically calculated price by setting the Price Fixed flag in the Marketplace Item Card. The Price Engine then skips this item during automatic calculation, and the manually entered price is retained.

This is useful for:

Promotional prices: Time-limited special offers
Special conditions: Individually negotiated prices with the marketplace
New products: Manual pricing at market launch
MSRP-bound items: Products with price binding

Calculation Log

Every single price calculation is logged in the calculation log. The log contains all details needed for traceability:

Field	Description
Entry No.	Unique sequential number
Calculation Date/Time	Time of calculation
Result	Outcome: Success, No Offer, Rejected, Error
Price List Code	The affected price list (e.g., SHOP)
Item No.	The item number
Vendor No.	The selected supplier (best offer)
Net Price	Net supplier price (before ancillary costs)
Purchase Price	Calculated purchase price (after ancillary costs)
Sales Price	Final sales price
Margin %	Applied margin percentage
Margin Amount	Absolute margin in euros
Rounding Method	Rounding method used
List Price Cap Applied	Was the price capped to MSRP?
Previous Price	Previous price (before this calculation)
Price Change %	Price change in percent
Result Details	Details on rejection or error

Color Coding

The log uses color codes for quick overview:

🟢 Success (green): Price successfully calculated and saved
🟡 No Offer / Rejected (yellow): No offer found or safety check failed
🔴 Error (red): Error during calculation

Log Cleanup

Via the actions on the log page, you can:

Delete All Entries: Clear the entire log (with confirmation dialog)
Delete Old Entries: Remove entries older than 30 days

→ Detailed description: Calculation Log

Interaction in the Hub Model

┌──────────────────┐     ┌──────────────────┐     ┌──────────────────────┐
│ 13+ Supplier     │────→│ Supplier Data    │────→│ Price Engine         │
│ Connectors       │     │ Pool             │     │ (11-Step Pipeline)   │
│                  │     │                  │     │                      │
│ Jarltech         │     │ • Net prices     │     │ • Best offer         │
│ BlueStar         │     │ • MSRP/List pr.  │     │ • PP calculation     │
│ Systeam          │     │ • Stock levels   │     │ • Margin + Rounding  │
│ Wave             │     │ • Manufacturer   │     │ • MSRP check         │
│ VEDES            │     │   data           │     │ • Safety checks      │
│ Toshiba          │     └──────────────────┘     └──────────┬───────────┘
│ GoDEX            │                                         │
│ Sato             │                                         ▼
│ ...              │                                ┌────────────────┐
└──────────────────┘                                │ BC Price Lists │
                                                    │ PP + SP        │
                                                    └────────┬───────┘
                                                             │
                                            ┌────────────────┼────────────────┐
                                            ▼                ▼                ▼
                                       ┌─────────┐    ┌──────────┐    ┌──────────┐
                                       │ SHOP SP │    │AMAZON SP │    │ OTTO SP  │
                                       │ €110.99 │    │ €122.99  │    │ €117.90  │
                                       └─────────┘    └──────────┘    └──────────┘

Frequently Asked Questions

What happens if the Price Engine is not installed?

Without the Price Engine, the hub works with manually maintained prices. The hub events (OnCalculateSalesPrice, OnCalculatePurchasePrice) are fired, but nobody responds to them. Prices must then be maintained manually in the BC price lists.

What happens if no supplier has an offer?

If no supplier offers the item (or all are filtered out), the result No Offer is logged. The existing price remains unchanged.

Can I set a different margin for a single item than for the category?

Yes, via the four-level margin hierarchy. Create an entry in the category margins with the specific combination of price list + category + supplier + item number.

What happens with a faulty supplier import?

The safety checks (Max Change %, Min Markup %) catch extreme price jumps. If an import accidentally contains a price of €1,000 instead of €100, the price change is detected as too high and rejected.

Can a price be lower than the purchase price?

The safety check Min Markup % prevents this. Set this value to e.g. 5% to ensure the sales price is always at least 5% above the purchase price.

How often are prices recalculated?

Automatically with every supplier import that detects a price change. Additionally, you can trigger a manual batch recalculation at any time.

The Hub Model – Overview of the hub architecture
Suppliers & Item Pool – How supplier data flows in
Central Item Pool – Where calculated prices are stored
Price Calculation Setup – Setup the Price Engine
Category Margins – Configure margins per product group
Supplier Costs – Ancillary costs per supplier