plus, kakashi would get a bonus for training, right? Probably the same amount of money for higher missions... but the pay can't be as important as room, and board...

(in case you didn't notice... kakashi's room was very similar to the room that naruto has... so I think most ninjas have rooms ....like a dorm. bigger houses like uchiha and hyuuga have mansions, and family's, like sakura's have actual houses)

so the pay isn't too much... probably