I havent even heard of any teacher or mentor getting money for helping with clubs or sports. I know that no teacher gets paid to coach or help with any club or sport. Maybe its because my team is from Canada not the usa.
In my opinion teachers should (edit: shouldn't) get paid to Volunteer. The teachers and mentors on my team, do so much the reward of knowing that they helped out students was a big enough reward for them. Our lead teacher spends Hours away from his family to help out, and goes for days when a competitions. I dont see why teachers and mentors should get paid for something they want to do, its almost like a hobby, You love doing it, its rewarding knowing you accomplished something, but you don't get paid for it.
Just my opinion though.
