Two-Sided Marketplace MVP: Scope, Cost, and Timeline

This worked example scopes a focused web marketplace where buyers discover listings, sellers manage supply, the platform coordinates checkout and payouts, and an admin team handles trust and disputes.

It is an illustrative planning range, not a quote. Reviewed 10 August 2026.

Must have

The release that proves marketplace liquidity

  • Buyer, seller, and administrator accounts with role-specific permissions.
  • Seller onboarding and listing creation with images, price, availability, and moderation state.
  • Buyer search, filters, listing details, saved items, and checkout.
  • Card payment, commission calculation, seller payout state, receipts, and refund handling.
  • Order lifecycle, buyer/seller notifications, basic reviews, reports, and admin intervention.

Should have

Trust and operations needed for a credible launch

  • Seller verification status and a visible buyer-protection policy.
  • Cancellation, refund, payout hold, and dispute escalation workflows.
  • Admin dashboards for listing, order, seller, payout, and report queues.
  • Privacy controls, accessibility review, audit history for sensitive admin actions, and operational alerts.

Post-MVP

Deliberately deferred scope

  • Native mobile apps and offline seller workflows.
  • Personalized ranking, dynamic pricing, advanced promotion tools, and loyalty.
  • Escrow, multi-currency settlement, cross-border tax automation, and complex split payouts.
  • Seller subscriptions, advertising products, warehouse integrations, and public partner APIs.

Visible assumptions

How this example reaches its range

  • This reproduces the marketplace calculator's starting selection with Seller payouts and disputes moved from Later to Should so the estimate covers the reviewed scope.
  • Base feature effort: 56 optimistic, 110 most-likely, and 194 pessimistic person-days; PERT expected effort is 115 person-days.
  • Public web, authenticated web, and an admin portal; three primary roles; standard design; small launch scale; one language; and one tenant.
  • Product management, design, QA, and DevOps/release coverage add 40%. Three platform surfaces add 28%, the third role adds 4%, and the selected accessibility allowance adds 8%.
  • Blended rate: €650 per person-day. Productive team capacity: 12 person-days per week. Discovery and release buffers add 1.5 weeks.
  • The 15% contingency applies to all three estimate bands. The combined factor is 2.315, producing about 129.6 optimistic, 266.2 expected, and 449 cautious person-days.

Using these assumptions produces an indicative cost range of approximately €84,000–€292,000 and an elapsed range of about 12–39 weeks.

Delivery phases

A practical implementation sequence

  1. Validate supply, demand, commission, protection, payout, refund, and dispute policies.
  2. Build identity, roles, listing model, seller onboarding, and admin foundations.
  3. Deliver discovery, checkout, order state, notifications, payouts, and support workflows.
  4. Run accessibility, payment, security, moderation, refund, and operational readiness testing before a controlled launch.

Main risks

Questions discovery must resolve

  • Who is merchant of record, and when is a seller entitled to a payout?
  • What evidence decides cancellations, refunds, chargebacks, and buyer/seller disputes?
  • Which seller or listing checks are manual, automated, or supplied by a payment provider?
  • What launch geography, currency, tax, privacy, and consumer-protection rules apply?

Try the scenario

Replace this example's assumptions with your marketplace decisions.

Reproduce this marketplace estimate Read the estimation methodology Compare export options