The verdict in three sentences
A spare parts B2B marketplace is funded by a commission of 8 to 15% on distributors' sales, which requires a gross merchandise volume of at least 5 to 10 million EUR per year to cover the platform and the team. There are two routes: a SaaS solution such as Mirakl or Izberg, from 50,000 EUR per year, or a custom build between 80,000 and 200,000 EUR excl. VAT. Either way, plan 5 to 8 months and as much energy for onboarding the 50 vendors as for the technology.
SaaS or custom: comparing costs over three years
SaaS vendors provide a multi-vendor catalogue, split order management and payouts out of the box. Custom builds, often on an open source base (Medusa, Sylius, Spree), give more freedom on technical parts search and on the business model, but require a team to keep them running.
| Item (2026 estimate) | Mirakl | Izberg | Custom (open source base) |
|---|---|---|---|
| Annual licence or subscription | 80,000 to 200,000 EUR | 50,000 to 120,000 EUR | 0 EUR (hosting 6,000 to 15,000 EUR) |
| Variable share of volume | 0.5 to 2% of GMV | 0.5 to 1.5% of GMV | 0% |
| Integration and storefront | 60,000 to 150,000 EUR excl. VAT | 40,000 to 100,000 EUR excl. VAT | 80,000 to 200,000 EUR excl. VAT |
| Launch timeline | 6 to 8 months | 5 to 7 months | 5 to 8 months |
| Annual enhancements | 20,000 to 50,000 EUR excl. VAT | 15,000 to 40,000 EUR excl. VAT | 30,000 to 60,000 EUR excl. VAT |
| Total 3-year cost (GMV 8 M EUR/year) | 450,000 to 950,000 EUR | 300,000 to 650,000 EUR | 220,000 to 425,000 EUR |
| Vendor lock-in | High | Medium | Low |
For a launch with 50 distributors, custom is often cheaper over three years. SaaS makes sense if you quickly target several hundred vendors, several countries and integration with varied ERPs through connectors that are already maintained.
Commission, business model and break-even
The commission must stay below the margin a distributor is willing to give up for a new customer. On industrial spare parts, that margin is often between 20 and 35%. A commission of 8 to 15% is therefore acceptable, especially if the platform brings buyers the distributor was not reaching.
| Annual GMV | Average commission 10% | Vendor subscriptions (50 x 150 EUR/month) | Total revenue | Estimated annual cost (platform + team of 3) |
|---|---|---|---|---|
| 2 M EUR | 200,000 EUR | 90,000 EUR | 290,000 EUR | 320,000 EUR |
| 5 M EUR | 500,000 EUR | 90,000 EUR | 590,000 EUR | 350,000 EUR |
| 8 M EUR | 800,000 EUR | 90,000 EUR | 890,000 EUR | 380,000 EUR |
| 12 M EUR | 1,200,000 EUR | 90,000 EUR | 1,290,000 EUR | 420,000 EUR |
| 20 M EUR | 2,000,000 EUR | 90,000 EUR | 2,090,000 EUR | 500,000 EUR |
Break-even therefore sits around 2.5 to 3 million EUR of annual GMV. Below that, you need to combine commission, vendor subscription and paid services (featured listings, logistics, purchase financing).
Vendor onboarding, product data and disputes
The real workload of a spare parts marketplace is data. A part is searched by manufacturer reference, by equivalent, by dimension and by compatible machine. You must normalize catalogues from 50 distributors in heterogeneous formats (Excel files, ERP exports, EDI feeds). Plan for:
- file and API import, with automatic quality checks on attributes;
- a cross-reference table between manufacturer part numbers, often 15,000 to 40,000 EUR excl. VAT to build;
- a supported onboarding path of 2 to 4 weeks per vendor;
- a clear dispute process (non-conformity, delay, return) with 48 h response times and funds held until receipt;
- 30 or 60 day payment terms for business buyers, through a B2B financing partner charging 1 to 3%.
Mini case study
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Daan, an Amsterdam founder with a background in industrial maintenance, brings together 50 distributors across the Netherlands and Belgium. He chooses a custom build at 140,000 EUR excl. VAT, with 45,000 EUR per year for run and enhancements, and a team of three at 210,000 EUR per year.
Year-two target: 6 million EUR of GMV at 11% commission, or 660,000 EUR, plus 90,000 EUR in vendor subscriptions. Revenue: 750,000 EUR. Annual costs: 255,000 EUR, plus depreciation of the build over three years, about 47,000 EUR. Estimated operating margin: about 448,000 EUR. In year one, with 2 million EUR of GMV, the platform remains slightly loss-making, which must be funded in the cash plan.
FAQ
How many vendors are needed to launch a B2B marketplace?
A credible launch needs 20 to 50 vendors covering at least 70% of the part families buyers search for. Below that, buyers too rarely find the reference and do not come back.
What commission rate should be charged?
Between 8 and 15% depending on product family margins: 8% on fast-moving, low-margin parts, 12 to 15% on technical or rare parts.
Is Mirakl suited to a launch?
Mirakl mainly targets operators that already have strong volume. With a minimum subscription of 80,000 EUR per year, it weighs heavily while GMV stays under 10 million EUR.
How is invoicing between vendors and buyers handled?
The simplest model is self-billing: the platform issues the invoice on behalf of the vendor and deducts its commission. Mandatory e-invoicing rules in the EU (and in France from September 2026) must be built in from the design phase.
What timeline should be planned?
Plan 5 to 8 months for the platform, and in parallel 3 to 4 months to recruit and onboard the first 50 vendors.
Let's scope your project. We scope your B2B marketplace (SaaS or custom, indicative budget 80,000 to 200,000 EUR excl. VAT, launch in 5 to 8 months, commission model). Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.