What an AI agent actually costs a business

Most of the market sells AI agents on a monthly plan: €350–700 a month, plus a one-time setup of €300–500. Rebuild charges the setup once and then per result — €6 per invoice actually resolved, €1.50 per call actually answered — with a €45 minimum in a quiet month and a ceiling a busy month can never pass. Everything below is where those numbers come from and what changes them.

What you are actually paying for

Three things sit inside the price, whoever you buy from:

• The model. Every message the agent reads and writes costs a fraction of a cent. For a business sending a few hundred emails a month, this is €5–40.
• The engine. The part that decides when to act, what to say, when to stop and when to hand over to a person. This is where the real work is.
• Someone watching it. Logs read, mistakes caught, wording adjusted as your business changes.

DIY tools sell you the first one and call it an AI employee. The €99/month chatbot is real, and so is the reason it sits unused after six weeks: nobody owned the other two.

What moves the price

The channel. Text work — email, forms, documents — is the cheapest to run, so it carries the lowest ceiling: €350 a month, whatever the volume. Voice costs more per minute and its ceiling is €500, because a phone call has to answer in under a second or it feels broken.

The integrations. An agent that reads Gmail and writes to Xero is a two-sign-in install. An agent that has to reach a twenty-year-old desktop system is a different job, and it should be quoted differently before you pay anything.

Volume. On a monthly plan you pay the same in your quietest month as your busiest, which is why quiet months are where those plans make their margin. Paying per result inverts that: a quiet month costs you the €45 minimum, and a genuinely busy one stops at the ceiling.

The costs nobody counts

1. The queue you already pay for. One person spending five hours a week chasing invoices at a loaded cost of €35 an hour is €760 a month, every month, forever.
2. The revenue that leaks. Enquiries answered the next day convert far worse than enquiries answered in a minute. That gap does not appear on any invoice.
3. The setup you do twice. Cheap tools get installed, half-configured, and abandoned. The second attempt costs more than doing it properly once.

The honest comparison

A part-time person to cover the same queue is €1,200+ a month, works set hours, and takes holidays. An agency doing it for you is €2,000+. An agent costs you €45 in a quiet month and never more than €350–700 in a busy one, works nights and weekends, and hands anything unusual to a human.

That is not an argument for replacing people. It is an argument for stopping people from doing the part of their job that a machine does better at 3am.

What to ask before you pay anyone

• Can I see everything it did, line by line?
• Does it run in draft mode first, with my staff approving?
• What happens when it does not know the answer?
• What does it cost to leave?
• Am I paying for work done, or for a month in which nothing happened?

If any of those answers is vague, the price is not the problem.

The short version

Budget €300–500 once to set it up, then pay for results: a quiet month should cost you almost nothing and a busy one should stop at €350–700 per agent. Compare it against the hours it removes, not against a free chatbot. If it does not pay for itself inside the first two months, it was the wrong queue.