The verdict in three sentences
A B2B marketplace has three critical bricks: vendor onboarding with KYC, automated payment splitting and dispute handling. The structuring choice pits a SaaS license (Mirakl from ~100,000 EUR/year) against custom build (60,000 to 150,000 EUR one-off): the license is faster but gets very expensive at scale, the custom build takes 3 to 5 months for an MVP but is yours. Your economics rest on the platform commission of 5 to 20 %, set from day one.
SaaS license or custom build: the true 3-year cost
The comparison is not about entry ticket but total cost of ownership. Here is a 2026 order-of-magnitude projection for a marketplace reaching 3M EUR GMV by year 3.
| Item | SaaS license (Mirakl-like) | Custom build |
|---|---|---|
| Setup | 40,000 - 80,000 EUR | 60,000 - 150,000 EUR |
| Annual license | 100,000 EUR+/yr | 0 |
| % on GMV | 1 - 3 % sometimes | 0 |
| Maintenance/yr | Included | 12,000 - 30,000 EUR |
| Total 3-year cost | 350,000 - 450,000 EUR | 100,000 - 210,000 EUR |
| MVP timeline | 2 - 3 months | 3 - 5 months |
| Code ownership | No | Yes |
A license makes sense if you target very fast growth and lack a technical team. Custom build becomes clearly cheaper as GMV grows, because you pay no percentage on your volume.
The critical modules you must not underestimate
A marketplace is not a store with several accounts. Three modules concentrate legal and financial risk. Here is their weight in a typical project.
| Module | Role | Budget share | Risk if botched |
|---|---|---|---|
| Vendor onboarding + KYC | Verify identity, IBAN | 15 - 20 % | Fraud, bank freeze |
| Payment split + payouts | Divide platform/vendor | 20 - 25 % | Payout errors |
| Dispute handling | Arbitrate buyer/seller | 10 - 15 % | Loss of trust |
| Multi-vendor catalog | Moderation, mapping | 15 - 20 % | Duplicates, quality |
| Vendor dashboards | Sales, payouts, stock | 10 - 15 % | Vendor churn |
| Billing / commissions | Auto calc per vendor | 10 % | Accounting disputes |
Payment splitting is the reactor core: each order must automatically divide the amount between the platform (commission) and the vendor(s), with a traced weekly payout. Always test this module with real amounts before any launch.
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Mini case study
Jean-Paul directs a building-materials wholesaler federation in Toronto and wants to pool 45 suppliers on a B2B platform with an 8 % commission. Custom quote: 95,000 EUR, MVP in 4 months. Year-1 target: 2M EUR GMV. Commission generates 2,000,000 x 8 % = 160,000 EUR of revenue in the first year. Against a license at 100,000 EUR/year plus 2 % GMV (40,000 EUR), the three-year cost gap easily funds the custom build, which then remains an asset of the federation.
FAQ
How much does a B2B marketplace cost in 2026? A custom build runs 60,000 to 150,000 EUR depending on modules, against a SaaS license from ~100,000 EUR/year. The MVP ships in 3 to 5 months.
What commission should I charge vendors? Between 5 and 20 % depending on sector and platform value (logistics, payment, visibility). Wholesale B2B often sits around 5 to 10 %, services up to 20 %.
Is vendor KYC mandatory? Yes as soon as you handle financial flows on behalf of third parties. You must verify identity, IBAN and legal status, which also drives your banking compliance and anti-fraud posture.
How does payment splitting work? On each order the amount is automatically divided between platform commission and vendor, then paid out (usually weekly). Test it with real amounts before going live.
License or custom build to start? A license reassures and accelerates if you lack a technical team. Custom build costs less at scale and is yours; it is the right call once GMV targets several million.
Let's scope your project. Describe your sector, target vendor count and commission model and we will quote the MVP, payment split and KYC module. 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.
