The licence is the part you can see, and it is not the expensive part

Documents going stale is the main cost, and it is not optional

The answers are only as current as the material behind them, so every policy change, price change and process change creates a small piece of work that nobody is assigned. It is not large, but it is recurring and it is invisible: nothing fails when a document goes out of date, the assistant simply becomes confidently wrong. An hour a month, named and owned, is the whole of the remedy.

Somebody has to read what it could not answer

The log of unanswered questions is only worth having if a person looks at it, and that is the hour most often budgeted at zero. Half an hour a fortnight is enough to see what keeps being asked and to decide whether it is a documentation gap or a boundary working as intended. Unread, the log is a feature nobody is using.

The refusal list needs revisiting, because the business changes

What the assistant declines to discuss was decided once, probably well, against a business that has since changed its products, its regulators or its staffing. Twice a year somebody should read that list and ask whether each entry is still right in both directions: still refusing what it should, and no longer refusing something that is now ordinary.

Budget the hours as hours, so they can be taken away

An unbudgeted hour is not free, it is taken from somewhere else, usually from the person who was best at the job that lost it. Naming the upkeep as two or three hours a month makes it visible, assignable and arguable, which is the only way it gets done. It also makes the comparison with doing nothing honest, because doing nothing has a cost too and it arrives later.