Migrating from BigCommerce to Magento, realistic timeline and cost?

For a typical mid-market store (1k, 10k SKUs, B2B + B2C, 2 years of order history): $15k, $30k and 8-12 weeks end-to-end.

Phases:

• Weeks 1-2: Discovery + architecture + Magento + Hyvä install + dev environment.
• Weeks 3-5: Catalog + customers + orders migration via Cart2Cart / LitExtension or a custom export-import. URL redirect map (BC URLs differ from Magento’s, SEO-critical).
• Weeks 4-7: Theme rebuild on Hyvä (BC Stencil themes don’t port; Hyvä is the modern replacement).
• Weeks 5-8: Payment / shipping / tax reconnection, B2B feature setup, app replacements (each BC app needs a Magento equivalent).
• Weeks 8-10: ERP / WMS / ESP integrations.
• Weeks 10-12: UAT, performance tuning, cutover with 14-day rollback window.

Faster & cheaper paths exist for very simple stores ($5k, $10k, 6 weeks). Bigger / heavier-customization stores creep to $50k+ and 16 weeks, budget accordingly.