What Drives the Cost of an Ecommerce Website?

Ask five agencies what an ecommerce website costs and you can get five answers that differ by a factor of ten. The spread is real, because "an online store" covers everything from a theme with twenty products to a custom build tied into inventory, an ERP and wholesale pricing. The useful question is which decisions move your ecommerce website cost, so you can make them on purpose.

This post splits the cost into the build (one-time) and the running costs (every month), and gives you a scoping worksheet to take into agency conversations. We don't quote prices; the point is to understand what you are paying for.

Two kinds of cost

Build costs get the store launched: strategy, design, development, product data, photography, integrations, testing and migration.

Running costs continue for as long as the store does: platform subscription, payment processing, apps, hosting if you self-host, maintenance, content and marketing.

Owners often compare build quotes and forget that running costs can outweigh the build over a few years. Ask every vendor for both.

What drives ecommerce website cost in the build

These are the decisions that move a build quote most, roughly in order of impact.

1. Platform and approach. A hosted platform such as Shopify with a customized theme is the lightest path. A fully custom design on a hosted platform costs more. A headless build, where a custom front end talks to the commerce platform through an API, costs more again and suits stores with specific performance, content or experience needs.
2. Catalog complexity. Twenty simple products and two thousand products with sizes, colors, bundles and subscriptions are different projects. Variants, options and filtering drive both design and data work.
3. Integrations. Each system the store must talk to adds scope: an ERP or inventory system, a warehouse or 3PL, accounting, a CRM, marketplaces such as Amazon, a reviews platform. Two-way inventory sync can be one of the larger line items.
4. Custom functionality. Wholesale pricing by customer, quote requests, product configurators, custom subscriptions, gated catalogs, artwork uploads for print orders.
5. Content and product data. Writing descriptions, cleaning spreadsheets and producing photography are routinely underestimated, and a store with weak images has to work much harder to sell.
6. Migration. Moving products, customers and orders from an old platform, and redirecting old URLs so search rankings carry over.
7. Design depth. A theme adjusted to your brand, versus custom templates for home, collection, product, cart and landing pages.
8. Accessibility and performance targets. Testing against a standard such as WCAG and against speed budgets adds time up front and saves trouble later.

Running cost drivers

Platform subscription. Shopify's Help Center describes the monthly price as a recurring subscription charge that varies by plan (it lists Basic, Grow and Advanced, with Plus priced on request). Annual billing charges the full year up front at a lower effective monthly rate.

Payment processing. Card processing fees apply on any platform. On Shopify, credit card rates vary depending on the plan you choose.

Third-party transaction fees. This one surprises people. Shopify charges third-party transaction fees when you use an outside payment provider to accept payments, and the rate varies by plan. According to the Help Center, you aren't charged those fees on orders processed through Shopify Payments, Shop Pay, Shop Pay Installments or manual methods such as cash, cash on delivery and bank transfer, and they don't apply to point-of-sale orders. PayPal transactions are exempt only if Shopify Payments is your primary provider. For stores created on or after May 12, 2025, the fees can also apply to orders paid partly with store credit or gift cards. If you need a particular gateway, include those fees in your comparison.

Apps. Most stores add apps for reviews, subscriptions, email, search or shipping. Shopify notes that apps bill on their own cycles, separate from your plan. Ten small subscriptions add up, so review them every quarter.

Maintenance. Updates, fixes, new landing pages and seasonal changes. Our post on website maintenance plans covers what that should include.

To compare options on equal terms, put them through the same sum, using each vendor's current published rates and your own sales forecast:

• Fixed cost per year = 12 x (platform plan + apps + maintenance).
• Variable cost per year = expected card sales x (processing rate + any third-party transaction fee rate).
• Three-year cost = build quote + 3 x (fixed + variable).

A plan with a higher monthly price and lower rates can come out cheaper once sales pass a certain volume, and this sum shows you where that point sits for your store.

Payment security and PCI scope

Every store that takes cards has security obligations. The PCI Security Standards Council says PCI DSS applies to all entities that store, process or transmit cardholder data, regardless of size. Eligible merchants validate compliance with a Self-Assessment Questionnaire (SAQ) built for their type of setup, and for small merchants the individual payment brands determine the validation requirements, so the Council points you to your acquirer (your merchant bank) or the payment brand.

What this means for cost: the more of the payment page your own systems produce, the more compliance work you take on. A PCI SSC FAQ explains the dividing line. When every payment page the shopper sees comes directly from a PCI DSS validated provider, through a redirect to the provider or an iframe from it, the store may qualify for SAQ A, the questionnaire for fully outsourced e-commerce. If any element of the payment page comes from the merchant's own website, it does not qualify, and setups where the merchant's site generates the payment form are the reason the separate SAQ A-EP exists. Outsourcing doesn't remove your obligations: the same FAQ notes that the main attack on a redirect or iframe is changing the code on the merchant's site. This is general information and does not replace compliance advice, so confirm your position with your payment provider and acquiring bank before choosing a checkout approach.

A scoping worksheet

Answer these before you ask for quotes, and send the same answers to every agency so the numbers are comparable:

• How many products, and how many variants per product?
• Do you sell to consumers, businesses, or both? Different prices for each?
• Which systems must connect, and which way does data move?
• Who writes product content, and who supplies photography?
• What is moving from an old platform: products, customers, orders, reviews, URLs?
• Which payment providers do you need? Any buy-now-pay-later or subscription requirements?
• Where do you ship, and how are rates calculated?
• Which features must exist at launch, and which can follow in a second phase?
• Who will run the store day to day, and how comfortable are they with the admin?

The launch-versus-later line is the biggest cost lever you hold. A store that launches with the essentials and adds features once real sales data comes in usually spends its budget better than one that tries to build everything up front.

Where stores overspend and underspend

Overspend: custom features that a well-chosen app already provides; a headless build for a small catalog; twenty page templates when six would do; animation nobody asked for on the checkout.

Underspend: product photography; product data cleanup; redirects during migration; checkout testing on real phones; support in the first month after launch, when most of the small problems surface.

How Pinn.Media scopes ecommerce work

We work from the worksheet above and lay out the build and the first year of running costs together, so there are no surprises later. For an Amazon product launch, our work covered packaging, photography, listing images, A+ content and video: the content side of ecommerce that budgets often miss. If you are planning a store or a rebuild, book a discovery call and bring your product list.