I suppose that depends on the teacher. Everyone sets their own prices, a portion of which goes toward the maintenance and upkeep of the hall itself. If you're worried, you might be able to barter lessons of your own in exchange for someone else's. We all learn from one another eventually.

[He's made up his mind on what he wants to order, but he'll wait for her to make her choice first.]

A lot of Heroes? Over fifty at least, though I've never thought to hold a formal count. Our numbers fluctuate frequently.

[He's surprised to hear that she is familiar, however, as she looks gentle and passive. Not only did she fight, she did so against monsters. That's impressive.]

Not to worry. Many of the monsters we fight have a tendency to drop money after they're defeated. There are numerous postings on the quest board as well where people can offer payment for services. There are plenty of ways to earn all you need to supply yourself.