This guide breaks the cost down by workstream and surfaces the BigCommerce-specific cost drivers: B2B Edition usage, multi-storefront architectures, option-set restructuring to Shopify variants, and headless decisions for brands considering staying on Hydrogen versus simplifying back to native Shopify Plus.
The hidden cost on BigCommerce migrations specifically: scope ambiguity. BigCommerce brands often arrive at migration with unclear scope decisions about which features stay headless and which simplify to native. Brands that defer these decisions into build phase consistently spend 15-25% more than brands that resolve scope during discovery.
By brand size
Cost ranges by brand size tier
$5M-$15M DTC brands
$80K-$140K
Standard B2C BigCommerce install, single storefront, under 10K SKUs, no B2B Edition. Cart2Cart or LitExtension automated path with Matrixify reconciliation.
$15M-$50M DTC brands
$140K-$250K
Active B2B Edition with price-list complexity, possible multi-storefront, up to 30K SKUs. iPaaS for dual-write cutover typically in scope. Heavier reconciliation work for option-set restructuring.
$50M+ brands
$250K-$700K+
Enterprise B2B, deep multi-storefront, possible headless setups, custom Stencil theme work. Hydrogen-on-Shopify decision affects total cost meaningfully.
By workstream
Cost breakdown by workstream
| Workstream | Range |
|---|---|
Discovery and planning Three to five weeks of discovery scaling with B2B and multi-storefront complexity. The discovery work is heavier than Magento because the architectural decisions (B2B model, multi-store consolidation, headless) are larger. | $10K-$30K |
Catalog migration with option-set restructuring BigCommerce options and modifiers map imperfectly to Shopify variants and product options. Reconciliation is the dominant catalog cost driver and consistently under-budgeted by teams unfamiliar with BigCommerce specifically. | $18K-$70K |
B2B migration (if applicable) BigCommerce B2B Edition customer groups and price lists to Shopify Plus B2B companies, locations, and catalogs. Active B2B operations consistently add this line at $15K minimum. | $15K-$60K |
Multi-storefront consolidation or migration Each BigCommerce storefront either consolidates into a single Shopify store, becomes a separate Shopify store, or stays headless. The decision drives the cost; each option carries different implementation work. | $15K-$60K |
Theme rebuild Premium template plus customisation. BigCommerce Stencil themes often have custom JavaScript and CSS work that has no Shopify-side equivalent; the rebuild cost is comparable to Magento. | $15K-$70K |
App re-implementation BigCommerce apps to Shopify equivalents. Subscription apps, reviews, search/filtering, loyalty. Standard but proportional to source app stack count. | $8K-$30K |
SEO migration audit BigCommerce URL structures are more standardised than WooCommerce, making the audit work cleaner. Eight-week post-launch monitoring is the same discipline as other platforms. | $10K-$40K |
iPaaS (frequently in scope) Multi-storefront or B2B brands almost always need iPaaS for the dual-write cutover. Celigo at mid-market; Boomi at enterprise. The case for iPaaS is stronger on BigCommerce than other source platforms. | $15K-$60K annually |
What drives the variance
Why cost ranges vary so much
B2B Edition complexity
No B2B: subtract $15K-$30K. Active B2B: baseline cost. Heavy B2B with hundreds of customer groups: add $30K-$80K. The single largest variance driver on BigCommerce specifically.
Storefront count
Single storefront: baseline. Two to three storefronts: add $20K-$50K depending on consolidation strategy. Four or more storefronts: add $50K-$150K, often with enterprise iPaaS in scope.
Headless decisions
Brands moving from headless BigCommerce can simplify to native Shopify (saves money long-term) or stay headless on Hydrogen (adds $30K-$80K to the build phase). The decision belongs upstream of cutover scope.
Option-set complexity
Standard option sets: baseline. Complex product configurators with multi-dimensional options: add $10K-$30K for the variant reconciliation work.
Custom Stencil theme work
Standard Stencil theme: minimal impact. Heavily customised Stencil with bespoke JavaScript and integrations: add $10K-$40K to theme rebuild work because the source theme cannot be reused.
Hidden costs
Cost lines operators forget to budget
Internal team time
$15K-$40K of internal time at loaded rates across the 16-28 week timeline. BigCommerce brands often have more sophisticated operations teams than Magento or WooCommerce equivalents, which can offset some agency cost but increases the internal coordination requirement.
BigCommerce overlap during dual-write
Source BigCommerce subscription continues during the cutover window and any dual-write period. Three to nine months of platform fees at BigCommerce Enterprise rates is real money — typically $5K-$30K of overlap cost.
iPaaS subscription for dual-write
Celigo or Boomi during the dual-write period. Most BigCommerce migrations involve iPaaS for at least three months; some convert to permanent fixtures. Plan the iPaaS subscription as part of the migration cost rather than as a post-launch surprise.
B2B customer comms
B2B customer relationships are higher-stakes than B2C. Plan proactive comms work specifically for the B2B segment around password resets, new ordering flows, and pricing-visibility changes. Often $2K-$8K in dedicated marketing and account management hours.