Ask most business owners what AI costs and they'll say £20 a month, because that's what ChatGPT costs. Ask a few who've been burned by a vendor and they'll say far more than it's worth. Both answers are wrong in the way that matters most.
The cost of AI for a small business depends entirely on what you're actually trying to do with it. So let's break it down properly.
The £20/month misunderstanding
ChatGPT Plus costs £20 a month. For what it is — a general-purpose AI you can ask questions and get answers from — that's genuinely good value. If you use it to draft emails, summarise documents, or think through problems, it earns its keep.
But it's a tool you use, not a system that works for you. Every time you want it to do something, you have to open it, write a prompt, review the output, and copy it somewhere else. Your time is still very much in the loop. That's not a criticism; that's just what it is.
The £20/month figure is real. The assumption that it represents "using AI in your business" is where things go sideways.
"ChatGPT costs £20 a month to subscribe to. The hidden cost is the hours you still spend prompting it every day."
The different tiers — and what you actually get
There's a spectrum of ways to bring AI into a business, each with a different cost structure and a different level of involvement required from you.
The cost nobody puts in the spreadsheet
There's a number missing from every AI cost comparison, and it's the one that matters most: the cost of your time.
If you're spending three hours a day on quoting, admin, or chasing enquiries, that time has a value. For most business owners it's worth £40–£100 an hour in terms of what they could otherwise be doing. Three hours a day, five days a week, comes to somewhere between £25,000 and £65,000 a year of your capacity, tied up in tasks that don't require your judgment.
This is the number most people don't calculate before asking what AI costs. When you do calculate it, the economics change completely.
- Time spent on quotes before: 2 hours per day
- Value of that time: £60/hour = £120/day = £600/week
- Cost of a custom quoting automation: £800 build + £120/month ongoing
- Break-even: less than two weeks
- After that: pure time recovered, every week, indefinitely
What custom-built AI actually costs in practice
At Agentrify, we build automation for businesses that have a specific problem worth solving. A voice-to-quote tool. An enquiry handler that responds out of hours. A lead monitoring system that surfaces new opportunities automatically. The kind of thing you'd otherwise spend hours on every week, done by a system that runs without you.
The typical structure is a one-off build fee — usually between £750 and £2,000 depending on complexity — and a monthly hosting and maintenance fee that covers the infrastructure, AI costs, and keeping everything updated as the technology improves. That monthly figure is typically between £100 and £200.
Compared to hiring someone to do the same task, or losing the equivalent hours of your own time, the numbers are not close.
The right question to ask
The question most people start with is: what does AI cost? The question that's actually worth asking is: what is it costing me not to automate this?
If the answer is significant time, real money, or consistent friction in your business, then the cost of fixing it is almost always less than the cost of leaving it as it is.
Not every business is at the point where automation makes sense. If your processes are inconsistent, or you're still figuring out what the workflow should look like, building on top of it too early creates its own problems. But for a business that has a repeatable, time-consuming task it does every day — quoting, follow-up, admin, reporting — the cost question answers itself fairly quickly.
"The right question isn't what AI costs. It's what the problem is costing you right now."
Where to start if you're not sure
The simplest version of this conversation is: tell us what eats your time. We'll tell you whether it's automatable, what it would cost, and whether the maths makes sense for your business specifically. If it doesn't, we'll say so.
Most businesses have one or two things that are clearly worth fixing. Finding those first, and building something small that genuinely works, is worth more than a large AI strategy that takes six months to implement and never quite fits how you actually operate.
The cost of getting started is usually much lower than people expect. The cost of not starting is usually higher than they realise.