Your store grows - and so do hidden costs. Estimate your five-year TCO.
A quick, free calculator based on 2026 market assumptions. See when a move to headless (Medusa.js) starts to pay off at your GMV level.
- Models informed by 16+ years in software delivery and 120+ shipped digital projects.
- One of the few Polish teams maintaining active open source for the Medusa.js ecosystem.Our Przelewy24 integration is public on GitHub. View repository →
- Unlike many agencies, we offer a fixed-price guarantee after the DDT (Discovery, Design & Technology) stage.
TCO calculator
Set the inputs to calculate your result
Change GMV, platform, or app costs. The result will update around your situation.
Non-financial upside of going custom (Medusa.js)
SaaS pain is not only cash - it is friction: API ceilings, support queues, and roadmap items that never get approved.
Owning the stack is not only about lower TCO. It ends the wait for a vendor roadmap. Your team can ship subscriptions, B2B configurators and bespoke promotions without negotiating with a platform provider or paying for every new marketplace feature.
Edge assumptions behind the algorithm (for skeptics)
Transparent simplifications in the demo model. A real quote always needs contracts, gateway rates, and integration maps.
- For SaaS we model an effective blended gateway fee around 2.15% plus a small per-order fixed (on the order of USD 0.30) averaged into the reference curve.
- For headless we assume no extra platform take-rate on turnover (beyond card-network/processor costs and your infra).
- Medusa.js CAPEX steps between scale tiers (build + integrations), it does not grow linearly with every GMV million.
Want to discuss your result?
Book a free 45-60 minute strategy session with a GMI e-commerce architect. You leave with specifics even if we never sign a build contract.
- A focused TCO pass on your real volumes and payment-gateway fees - not generic industry tables.
- Migration risk notes and a starter Medusa.js rollout timeline that keeps sales running (dual run, phased cutover).
- A straight answer on whether a fixed-price guarantee after our DDT (Discovery, Design & Technology) stage fits your case.
The primary button opens the contact section on the gmi.software homepage.