Online store: what to build it with and what it costs

Sell products online: a catalogue, a cart, checkout and order emails.

Sample PRD

Product catalogue
Cart and checkout
Order confirmation emails
Inventory

What it needs

One-off payments: customers pay at checkout
Merchant of record (handles sales tax / VAT) (nice to have): someone handles sales tax and VAT for you
Transactional email: order confirmations and shipping emails
Postgres: products, orders and stock

MVP: about 100 users, $0/mo

Someone with an idea or a solo founder. Built with an AI app builder: describe it and it builds and hosts it.

What	Pick	Monthly
AI coding agent	Base44 Starter	$16
Email	Mailgun Free	$0
Payments	Stripe Standard (US cards)	$43.80
Analytics & errors	PostHog Free	$0

First cost jump: Mailgun: Free limits reached, upgrade to Basic

Open the full MVP plan · Use the MVP stage in Claude

Growth: about 10,000 users, $23.05/mo

A funded team or one with traction. Built with an AI coding agent for each of about 3 developers.

Error tracking: know when something breaks
Daily backups: daily backups once real people depend on it

What	Pick	Monthly
AI coding agent	Augment Code Standard	$20
Hosting	Heroku Basic dyno	$7
Database	Neon Launch	$1.05
Sign-in	Auth0 Free	$0
Email	Amazon SES A la carte	$15
Payments	Stripe Standard (US cards)	$4,380
Analytics & errors	PostHog Pay as you go	$0

First cost jump: Auth0: Free limits reached, upgrade to B2C Essentials

Open the full Growth plan · Use the Growth stage in Claude

Scale: about 100,000 users, $260.64/mo

An established product. Built with an AI coding agent with team billing and admin for about 10 developers.

Error tracking: know when something breaks
Daily backups: daily backups
Point-in-time recovery: restore to any minute after a bad deploy
Multi-factor authentication: two-factor sign-in for accounts worth stealing

What	Pick	Monthly
AI coding agent	Augment Code Standard	$20
Hosting	Fly.io Machine, shared-cpu-1x with 256MB RAM	$62.19
Database	DigitalOcean Managed PostgreSQL Single node (1 vCPU, 1 GiB RAM, 10 GiB disk)	$19.45
Sign-in	WorkOS AuthKit	$0
Email	Amazon SES A la carte	$150
Payments	Stripe Standard (US cards)	$43,800
Analytics & errors	Sentry Team	$29

First cost jump: DigitalOcean Managed PostgreSQL: Single node (1 vCPU, 1 GiB RAM, 10 GiB disk) limits reached, upgrade to Single node (1 vCPU, 2 GiB RAM, 30 GiB disk)

Open the full Scale plan · Use the Scale stage in Claude

What drives the cost

Payment fees: a percentage of every sale
Order and shipping emails
Hosting stays small until traffic is large

Lock-in

Saved cards and subscriptions are hard to move between payment processors; ask about card export before you choose.

Use this in Claude (with Kong Reviews connected at https://kongreviews.com/mcp)

What do I use to build this?
And how much will it cost?What do you want to build?

Describe it in a sentence, like “an app that tracks the beans in my pantry”. You get what to build it with, what it runs on, and what it costs now and as it grows, with a source for every price.Describe it and press Plan. You get what to build it with, what it runs on, and what it costs now and as you grow, after the credits you qualify for.

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Recordings of the actual app. Inputs are illustrative; Billing shows an example account.

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I’m building a booking app for yoga studios with sign-in, payments and email reminders. What should it run on, and what will it cost at 20,000 users?

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Online store: what to build it with and what it costs

Sample PRD

What it needs

MVP: about 100 users, $0/mo

Growth: about 10,000 users, $23.05/mo

Scale: about 100,000 users, $260.64/mo

What drives the cost

Lock-in

What do I use to build this?And how much will it cost?What do you want to build?

What Are You Building?

Prices read from each vendor’s own pricing page

One placefor every stack decision.

Plan

Cost as you grow

Vendors

Audit

Billing

Showcase

Give your AI assistantaccess to Kong Reviews.

See what real productsare built on.

How services are ranked

See what startups build on.

Already built?Start from what you run.

Pick what works.Build what’s next.

Audit Your Stack

What's it built on?

What it runs on

What matters

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My Stacks

Billing

Vendors

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Showcase

Built Something?

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Missing a Vendor?

Questions

Pick what works.Build what’s next.

What do I use to build this?
And how much will it cost?What do you want to build?

One place
for every stack decision.

Give your AI assistant
access to Kong Reviews.

See what real products
are built on.

Already built?
Start from what you run.

Pick what works.
Build what’s next.

Pick what works.
Build what’s next.