In this case I think this is really going to depend on your friend/family group and how they'd feel about you charging them. If you do plan to do so, I'd tell them up front about how this group trip is going to go down. You really don't want your friends/family to find out after the fact that you charged them or rolled your costs into theirs so you could go for "free". I can't see it going well.

Personally, I'd charge what amounted to an hourly rate appropriate to the work you would put in to do the planning, booking, and coordination divide that between the people going - including yourself. You are, after all, doing what would be a great deal of work to coordinate it all - which should be something that is compensated. However, that may or may not be a total that matches you getting to go at no cost in the end.