Nearly every ecommerce quote you receive is really an answer to one question you may not have been asked. Are you buying a platform you configure, or software you own? Shopify and a custom build are both sold as “ecommerce development”, they cost different orders of magnitude, and the right answer is usually the cheaper one.
Shopify or BigCommerce until a specific named requirement makes it impossible.
Subscriptions compound and each app is a dependency that can break or be abandoned.
Right when content and merchandising are a genuine differentiator, not before.
Fraud, tax and uptime become permanently yours. Only for genuinely unusual commerce.
Platform, custom, or headless
| Route | What you get | Right when | The real cost |
|---|---|---|---|
| Hosted platform (Shopify, BigCommerce) | Checkout, payments, PCI scope and hosting handled for you | Standard catalogue and standard checkout, which is most stores | Monthly fees plus per-transaction cuts, and hard limits on checkout logic below the top tier |
| Platform plus apps | The gaps filled by third-party apps | You need a handful of specific behaviours | App subscriptions compound, and every app is a dependency that can break or be abandoned |
| Headless | Custom storefront, platform commerce engine behind it | Content and merchandising are a genuine differentiator | You now own a frontend, with its own build, hosting and performance work |
| Fully custom | Complete control of catalogue, pricing and checkout | Genuinely unusual pricing, B2B contracts, or complex fulfilment | You inherit PCI scope, fraud, tax and uptime, permanently |
The honest default is a hosted platform until a specific, named requirement makes it impossible. “We might want flexibility later” is not that requirement, and it is the most expensive sentence in ecommerce procurement.
What actually drives the cost
- Catalogue complexity. Variants, configurable products, bundles and per-customer pricing each multiply the data model and the testing surface.
- Integrations. ERP, warehouse and fulfilment, tax, and accounting. Order data has to reconcile across all of them, and reconciliation is where the hidden work lives.
- B2B requirements. Quotes, approval chains, credit terms and contract pricing turn a store into an application.
- Migration. Moving an existing store means products, customers, order history and every URL. The redirect map is not optional and is routinely forgotten until traffic drops.
- Performance. Conversion tracks page speed closely enough that it belongs in scope from the start, not in an optimisation phase afterwards.
Replatforming without losing your search traffic
The most expensive ecommerce mistake we see is a technically clean migration that silently loses organic rankings, because the SEO work was treated as a marketing task after launch rather than an engineering deliverable during it.
- Map every old URL to a new one before launch, including retired products, which should go to a relevant category rather than to a generic 404.
- 301, never 302. Temporary redirects do not pass ranking signals, and the difference is invisible until it is not.
- Keep the structured data. Product, price, availability and review markup drive how listings appear, and it is easy to lose in a rebuild.
- Benchmark before you cut over. Capture rankings, traffic and Core Web Vitals first, so a regression is provable rather than arguable.
What to ask any ecommerce development company
- Which platform do you recommend, and when would you recommend against it? An agency that recommends the same platform every time is telling you about their bench, not your business.
- Who owns the apps and integrations? Accounts and licences should be yours.
- Show me a migration you did, with the redirect map. This single artefact separates the careful from the confident.
- What happens on the busiest day of the year? Load testing before peak, not after it.
- Who is on call during a checkout outage? Agree it before you need it.
Ecommerce development with Sthenos
We build and replatform ecommerce systems for organisations across Maryland and the Washington DC region, delivered through an established engineering partnership with NeoSOFT. We will tell you when a hosted platform is the right answer even though it is the smaller engagement, because inheriting PCI scope and fraud handling for no reason is not a favour. To scope a build, a replatform or a set of integrations, talk to our engineers. Related: our ecommerce practice and what a redesign costs.