How much does an AI assistant actually cost to run?
The build is a one-time number. The part people forget is what it costs every month — and how to keep that small.
Most quotes for an AI assistant cover building it. Fewer people ask the question that matters six months in: what does it cost to keep answering questions every day?
Running cost comes down to three things — how many questions it answers, how much text each answer involves, and which model does the work. A support bot handling a few hundred questions a day on a mid-tier model usually costs less per month than a single part-time hire. But careless design can multiply that by ten.
The biggest lever is model choice. Using a top-tier model for every reply is like couriering every letter — sometimes necessary, usually not. We route simple questions to cheaper models and reserve the expensive one for the hard cases.
The second lever is retrieval. A well-built assistant only sends the relevant slice of your documents to the model, not the whole library, on every question. Done right, that alone can cut running cost dramatically.
We estimate all of this before building, so you approve a system that’s affordable to run — not just one that’s impressive in a demo and painful on the invoice.