There is absolutely no way a TA should be charging $250 for a simple commisionable hotel booking. It would make sense for an agent to charge a fee for services if you were asking the TA to do substantial planning/legwork for you for things that were not commissionable.

My guess is that it was a polite way for the agent say she was not interested in the booking.

Plenty of TAs will do even small bookings for no fees, especially if you already know what you want.