The invoice nobody adds up
A custom cake bakery came to me with the usual plan for taking custom orders online: a quote app, a deposit app, and a form builder to collect the cake details. Each one was cheap on its own, and each one looked like a sensible choice.
Together they would bill every month, the deposit apps capped how much the owner could take, and none of them would know the others existed. The real workflow, from "I want a cake" to "balance paid", would still have run through her inbox.
That's the pattern I see most. Nobody decides to spend a few hundred dollars a month on apps. It happens one sensible install at a time, and the total is never on a single invoice.
Nobody decides to overspend on apps. It happens one sensible install at a time.
What a monthly app really costs
The price on the app listing is only the first of three costs.
1. The sticker price
The monthly fee. Easy to see, easy to accept, and usually the smallest part of the story once a store is growing.
2. The growth tax
Many apps charge per order, per item or as a percentage of revenue. Recharge, one of the most used subscription apps, lists its Starter plan at $99 a month plus 1.49% and 19¢ per transaction. On a store doing 400 subscription orders a month at $50, that's:
Worked example
$99 + (1.49% × $20,000 = $298) + (400 × $0.19 = $76) = $473 a month, or about $11,350 over two years, before a single order more. The better the store does, the more it pays.
3. The stack tax
One job often needs two or three apps: one for the form, one for payments, one for reminders. You pay for all of them, maintain three settings screens, and still hand-copy data between them. Every app that loads on the storefront also adds its own scripts, which is a common reason stores get slower over time.
Run your own numbers
Pick the apps you actually pay for. Every app and plan below is taken from its Shopify App Store listing, with the same fees and limits. The pink line is your apps, adding up month by month. Then pick which of my custom builds does the same job: its one-time price and running cost appear as the violet line, and where the lines cross is your break-even.
Calculator · real App Store prices, checked 26 October 2026
Start from a typical stack, then swap in the exact apps and plans you pay for.
Your app stack
- S: Request a Quote
Quotes
Unlimited quotes
- Downpay
Deposits
Order value up to $10,000
Unlimited submissions
Add an app
Compare with my custom build
Pick the build that does the same job. Its one-time price and running cost are filled in for you.
Running cost: about $45/mo hosting and database. Starting price; the final price depends on scope.
Apps cost this month
$75
Apps over 24 months
$1,797
The custom ordering app (from $75) pays for itself in month 3.
By month 24 that's $642 that stays in the business, and the gap widens as orders grow.
Prices from each app's Shopify App Store listing on 26 October 2026. Where an app lists a fee range, the lowest is used, so app costs are never overstated. One item per order assumed. Plans change, so check the listing before deciding.
The calculator compares cost only. It doesn't count the hours your team spends moving data between apps, which is often the bigger saving.
What custom really costs
A fair comparison has to be honest about the other side too. A custom build is not free after launch.
- The build itself. A one-time cost, quoted for your scope. Additions later are quoted separately, only when you need them.
- Running costs. Hosting and a database. On professional plans that's about $45 a month (Vercel Pro $20 + Supabase Pro $25). Free tiers exist, but they're meant for personal or small projects, not a live business tool.
- A yearly check. Shopify releases a new API version every quarter and supports each for at least 12 months, so a custom app needs a small version update about once a year.
- Someone who knows it. You need a developer you can call. The code and data are yours either way, so you're never locked in.
What you get in return: one tool shaped around how you actually work, no per-order fees, nothing extra on the storefront, and your data in a place you control.
Three stores, three answers
The same question has had different answers depending on the business. These are from my own work.
Bakery · Miami
Three apps replaced by one, inside Shopify admin
Request, quote, deposit and balance in one place, with invoices sent as Shopify draft orders. No app subscription, no cap on deposits.
See the cake ordering appSubscription brand · UAE
Billing apps would take a cut of every order
The business needed letters, recipients, labels and refund rules, which billing apps don't do. A custom admin handles all of it, at 0% per order.
See the operations backendBook retailer · 4 stores
Four order-value features, no new monthly app
Bundles, frequently bought together, cart upsells and a prepaid checkout rule, built on Shopify Functions across four stores.
Read the case studyWhen you should not build custom
This matters as much as the rest. I tell clients not to build when:
Keep the app if…
It costs little and does the job. A $20 app that works is not a problem worth a project.
It's a commodity done well. Email marketing, reviews and accounting sync are mature products built by large teams. You won't build a better one for less.
You're still testing the idea. Use an app to prove customers want it. Build once you know they do.
Nobody will own it. A custom tool needs someone to call when Shopify changes. If that's not in place, wait.
A 60-second decision
Tick what's true for your store.
Your apps are probably fine.
Nothing here is costing you much yet. Revisit when orders grow or a new app joins the stack.
Questions
How long does a custom Shopify app take to build?
It depends on the scope. From my own builds: a storefront feature like a jersey personalizer took about 3 days, a custom ordering app with quotes and deposits about 2 weeks, and a multi-store inventory dashboard about 2 months, built section by section.
Will a custom app slow my store down?
An admin app runs inside Shopify admin, not on your storefront, so shoppers never load it. Storefront features can be lighter than general-purpose apps because they only include what your store uses.
What happens when Shopify updates its API?
Shopify releases a new API version every quarter and supports each one for at least 12 months. A custom app needs a version check about once a year, which is a small, predictable job rather than a rebuild.
Who owns the code and the data?
You do. With a custom build the code lives in your repository and the data in your own database or Shopify, so there's nothing to export or lose if you stop working with a developer.
Send me your app list.
Tell me which apps you pay for and what they cost. I'll tell you which ones to keep, which could go, and what a custom version would cost, if it's worth it at all.