The verdict in three sentences
Migrating from an ageing catalogue site (PrestaShop, Magento 1) to a modern B2B platform costs 40,000-120,000 EUR in 2026, depending on whether you re-platform onto Shopify Plus/Adobe Commerce or rebuild custom. The project runs 3-6 months and involves migrating 8,000-40,000 products plus order history. The line item that sinks projects is not tech but SEO: without a rigorous 301 redirect plan, you lose 20-40 % of organic traffic.
SaaS re-platforming or custom rebuild?
| Criterion | SaaS re-platforming | Custom rebuild |
|---|---|---|
| Budget | 40,000 - 75,000 EUR | 70,000 - 120,000 EUR |
| Timeline | 3 - 4 months | 4 - 6 months |
| Native B2B features | Good (limits) | Unlimited |
| Subscription / licence | 2,000 - 3,500 EUR/mo | Hosting 200 - 700 EUR/mo |
| Checkout customization | Limited | Total |
| Data migration | Tooled | Bespoke |
| Maintenance | 800 - 1,500 EUR/mo | 1,000 - 2,000 EUR/mo |
| Reversibility | Low | High (code delivered) |
SaaS re-platforming suits SMEs that want speed and outsourced infra. Custom wins when business logic (pricing, credit, ERP) is specific or when volume makes the SaaS subscription costlier than self-hosting.
Migration phases
| Phase | Content | Typical duration |
|---|---|---|
| 1. Audit & mapping | URLs, data, integrations, existing SEO | 2 - 4 weeks |
| 2. Design & mockups | B2B journeys, accounts, pricing | 3 - 5 weeks |
| 3. Build & data migration | Products, customers, history | 6 - 12 weeks |
| 4. 301 redirects & QA | SEO plan, tests, ERP | 2 - 4 weeks |
| 5. Cutover & hypercare | Go-live, monitoring | 1 - 2 weeks |
Budget by line item (2026 order of magnitude)
| Item | Range (EUR) |
|---|---|
| Audit & scoping | 3,000 - 8,000 |
| B2B UX/UI | 6,000 - 18,000 |
| Platform development | 18,000 - 60,000 |
| Data & catalogue migration | 5,000 - 15,000 |
| ERP connector | 6,000 - 15,000 |
| SEO & 301 redirects | 3,000 - 8,000 |
| QA & hypercare | 4,000 - 10,000 |
SEO risks: the line item you cannot miss
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| Risk | Impact | Countermeasure |
|---|---|---|
| Changed URLs without 301 | -20 to -40 % traffic | Exhaustive redirect plan |
| Lost tags & structured data | SERP drop | Migrate title/meta/JSON-LD |
| Long cutover downtime | Partial de-indexing | Cutover < 4 h, DNS prepped |
| Truncated catalogue content | Lost long tail | Migrate full descriptions |
| Sitemap not submitted | Slow re-indexing | Sitemap + IndexNow at go-live |
Mini case study
Sarah is GM of a Dubai electrical-supplies trading SME: 22,000 SKUs, a 2016 PrestaShop on its last legs. She budgets 86,000 EUR for a custom rebuild over 5 months, with an ERP connector and SEO plan. Cutover happens on a Sunday, downtime 3 h 10. Thanks to 4,200 301 redirects, organic traffic returns to baseline in 5 weeks then grows +15 % over six months, driven by the new reorder journeys. The commercial productivity gain (self-service) covers the 1,500 EUR/month maintenance from the first quarter.
FAQ
How long does a B2B migration take? From 3 to 6 months depending on data volume and integration complexity. Underestimating the audit phase is the classic mistake: it is what secures SEO and the ERP.
Will I lose my rankings? Not if the 301 redirect plan is exhaustive and tested before cutover. A 2-5 week dip is normal; without a plan, loss can reach 40 % and last months.
Can we migrate without service interruption? We target under 4 hours of downtime by prepping DNS, freezing orders during cutover, and switching during a low-activity window (night or weekend).
Must everything migrate, including history? Order history and customer accounts are essential in B2B (reorders, credit). Dead data (obsolete products, inactive accounts) can be archived rather than migrated.
SaaS or custom for an SME? SaaS is faster and outsources infra; custom wins on reversibility and TCO above a certain volume. The choice depends mostly on how specific your pricing logic and ERP are.
Let's scope your project. Send us your SKU count, current platform and ERP integrations: we will frame SaaS or custom, with an indicative budget (40,000-120,000 EUR) and a secure cutover plan. 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.