What an Ecommerce Replatform Costs, Including the Migration

A replatform is expensive in ways that don't show up on vendor pricing pages. Here's a realistic breakdown of where the money goes, including the migration work most teams underestimate.

The Licence and Infrastructure Bill Is the Easy Part

Platform costs are well-documented. Shopify Plus starts at $2,300/month. Commercetools bills on API call volume, typically landing between $50,000 and $150,000 per year for a mid-size catalogue. BigCommerce Enterprise is usually quoted in the $30,000–$150,000 annual range depending on GMV. SAP Commerce Cloud can run $250,000+ annually before any implementation work.

Cloud infrastructure for self-hosted or hybrid setups adds another layer. A production-grade setup on AWS or GCP, with proper redundancy, CDN, and staging environments, typically runs $3,000–$12,000/month depending on traffic and catalogue size.

These numbers are easy to find. The harder costs are below.

What Does the Actual Migration Cost?

This is where most budgets break down. The platform fee is a line item. The migration is a project, and projects have scope creep.

Data Migration

Product catalogues are almost never clean. Expect to spend real engineering hours normalising SKUs, mapping attribute schemas, reconciling duplicate records, and handling localisation if you sell in multiple regions. A catalogue of 50,000 SKUs with a messy attribute structure can take 4–6 weeks of engineering time just to clean and transform before a single record is imported.

Customer data migration adds compliance overhead. GDPR and India's DPDP Act both require that you can demonstrate lawful basis for transferring personal data to a new processor. If your old platform stored passwords in a format the new one won't accept (which is common), you'll need a forced-reset flow at cutover.

Order history is often the most underestimated piece. If your finance team or warehouse team queries historical orders through the storefront or its admin, you need that data in the new system, not just archived. Migrating five years of orders with associated line items, fulfilment statuses, and returns typically takes two to four weeks of dedicated backend work.

Integrations

Most legacy ecommerce stacks have between 8 and 20 active integrations: ERP, WMS, PIM, payment gateways, loyalty platforms, review platforms, email ESPs, analytics, tax engines, and so on.

Some will have native connectors on the new platform. Many won't. Budget for at least 30–40% of your integrations needing custom middleware or significant configuration work. If you're on SAP or Oracle for ERP, assume custom integration work regardless of what the platform's marketplace claims.

Payment gateway migration deserves its own line. If you're moving from one Stripe integration to another Stripe integration, it's straightforward. If you're changing PSPs or moving from a platform-native checkout, you'll need to handle tokenisation portability. Most PSPs will cooperate on token migration, but it requires a formal request, a data export in a specific format, and an import window coordinated with your new PSP. Plan 6–8 weeks for this process.

Frontend Rebuild

Few teams budget this correctly. Migrating platform does not mean your existing frontend transfers over. Even if you're moving from one headless setup to another, the component library, routing logic, and API calls are all platform-specific.

A full storefront rebuild on a React-based headless stack (Next.js + a commerce API) typically runs 12–20 weeks for a team of three to four frontend engineers, depending on the number of page templates and the complexity of the product discovery experience. That's a meaningful chunk of salary or agency cost.

If you're moving to a platform's native theme system (Shopify's Liquid, for instance), it's faster, but you're accepting constraints on what you can build.

Hidden Costs That Show Up After Go-Live

SEO is the most common post-launch surprise. URL structures almost always change in a replatform. If your redirect mapping isn't complete and validated before cutover, you'll see organic traffic drops within days. A catalogue with 10,000+ product URLs needs a systematic redirect audit, not a spot-check. Tools like Screaming Frog and Ahrefs can help, but someone has to do the work.

Performance regression is another one. Your old platform may have had years of caching optimisation baked in. The new one ships with defaults. Expect 4–8 weeks of post-launch performance tuning before you're back to baseline Core Web Vitals scores.

Team retraining is easy to forget. Every internal user who touches the admin, from merchandisers to customer service agents, needs to learn the new system. If you're moving from Magento to Shopify Plus, the admin experience is radically different. Factor in documentation, training sessions, and a dip in operational efficiency for 4–6 weeks post-launch.

How Long Does a Replatform Actually Take?

Company Size	Catalogue Complexity	Realistic Timeline
Small (< 1,000 SKUs, < 5 integrations)	Low	3–5 months
Mid-market (1,000–50,000 SKUs, 8–15 integrations)	Medium	6–10 months
Enterprise (50,000+ SKUs, 15+ integrations, multi-region)	High	12–18 months

These are from-kick-off-to-live timelines, not time-to-start-development. Discovery, vendor selection, and contract negotiation typically add 4–8 weeks before a line of code is written.

Teams consistently underestimate by 30–40% on first estimate. The most common reasons: integrations that turn out to be undocumented, data quality worse than expected, and frontend scope that expands once stakeholders see what's possible.

Build the Business Case Before Signing Anything

A replatform budget for a mid-market retailer typically looks like this:

• Platform licence: $50,000–$150,000/year
• Implementation (data, integrations, frontend, QA): $200,000–$600,000 one-time
• Infrastructure: $5,000–$15,000/month
• Internal team time (product, engineering, ops): often uncounted, typically 20–40% of total project effort

The total cost of ownership over three years for a mid-market replatform usually lands between $800,000 and $2,000,000 when you include all of the above. That number is not a reason not to replatform. It's a reason to be honest about the budget from the start, rather than discovering it halfway through.

If your current platform is genuinely blocking revenue growth or creating unacceptable operational risk, the investment is justified. If you're replatforming because the current one "feels outdated," the cost-benefit case is harder to make.

Conclusion

The platform fee is rarely the problem. The migration is. Get a detailed scope of your integrations, your data state, and your frontend requirements before you commit to a timeline or a budget. Talk to the teams who've done it on the platform you're evaluating, not just the vendor's sales team.

If you're planning a replatform and want an honest technical assessment of what your specific stack will actually cost to move, that's a conversation worth having before you sign a contract.

---

FAQ

How much does it cost to migrate from Magento 2 to Shopify Plus? For a mid-size catalogue (10,000–50,000 SKUs) with 8–12 integrations, expect $150,000–$400,000 in implementation costs, plus platform fees. Magento migrations are particularly involved because of the custom module ecosystem. Most modules have no direct Shopify equivalent and need to be rebuilt or replaced.

Can we run old and new platforms in parallel during migration? Yes, and for anything other than a small store, you should. A parallel-run period of 4–8 weeks lets you validate data integrity and integration behaviour before cutting over traffic. It adds cost (you're paying for two platforms temporarily) but significantly reduces go-live risk.

How do we handle SEO during a replatform? Map every indexed URL to its new equivalent before launch. Use a 301 redirect for all moved pages. Submit an updated sitemap to Google Search Console on launch day. Monitor crawl errors daily for the first two weeks. Expect some ranking fluctuation for 4–8 weeks regardless of how well you execute the redirect mapping.

What's the biggest replatform mistake teams make? Underestimating integration work. Teams typically scope the big integrations (ERP, payment) and forget the long tail: review platforms, loyalty systems, affiliate tracking, internal reporting tools. The long tail usually accounts for 30–40% of total integration effort.

Should we build headless or use the platform's native storefront? Headless gives you full control over the frontend and better performance ceilings, but adds complexity and cost. A Next.js + commerce API stack requires a capable frontend team to build and maintain. Native themes are faster to launch and cheaper to maintain, but you're constrained by what the theme system supports. The right answer depends on how differentiated your frontend experience needs to be.

Have a project in mind? Contact Sodio Technologies to discuss your requirements and explore the right technology solution for your business.