We built 5 marketplaces in 2025. Here is what each actually cost, what took the longest, and where founders overspend.

By David Friedman , Founder of AppBrewers

Marketplaces are the most complex web apps you can build. Two-sided platforms need user management, payments, reviews, search, and admin dashboards. We built 5 marketplaces in 2025. Here is what each actually cost.

What Makes Marketplaces Expensive

Feature Complexity Why It Costs More

Multi-vendor accounts High Each vendor needs their own dashboard, payouts, and tax handling.

Escrow payments High Holding funds until delivery requires legal compliance and banking integration.

Search and filtering Medium Elasticsearch or Algolia adds infrastructure cost and dev time.

Reviews and ratings Medium Fake review detection, moderation, and dispute handling.

Real-time messaging Medium Chat between buyers and sellers with notifications.

Commission logic High Variable fees, subscriptions, and promoted listings.

Admin moderation Medium Content flagging,…