I am not really opposed to GB facilitators receiving something for their time and energy. But, as I noted, the main determinant should be his cost.
In general, I think if one fronts the money himself, it is his right to set the price as he sees fit. If one collects money in a GB fashion, it is OK to get something out of it as I noted (e.g., the cost of one of the units), but the goal should not be to maximize profit since it's not one's own money at stake. Hopefully that's not what he has in mind.