Well I think this question is phrased poorly. Everyone pretty much much smokes with friends, its not like everyone has their own stash and 4 people sit with personal bowls. Do people actually ask for money when someone hits your bowl.

"Hey, that his is gonna cost ya 50 cents, hand it over"

I think a better question is how much bud have you handed over to someone for them to choose who smokes it. I have given away a half 8th on two occasions for friends to smoke not expecting anything in return.