Many places won't do seperate checks for larger parties (and they will include gratuity in the bill). I know that the last two parties I organized (about 20 people each), they would not split the check for food (but they would open seperate bar tabs for people). That one was more of a dinner and I had to preorder food for everyone. It should've come out to $20 per person, but I got stiffed by several people (included two who didn't show up at all) and ended up having to pay about $150 out of my own pocket. The second party was more casual and it was a flat $15 fee per head which included salads, appetizers, non-alcoholic beverages and the tip. So honestly, $15 doesn't sound like much to me, and I can understand them wanting to get money from people ahead of time, especially if the place won't split the check 15 different ways. Otherwise it would be a whole different sort of fight, "well, I only had two cheesesticks, but Bob ate seventeen buffalo wings, so I don't think I should have to pay as much..." etc. etc. So I would suggest either sucking it up and going without complaints, or declining. Please try not to assume the worst of people. I would be shocked and horrified and very, very hurt if people actually thought I was skimming from what they put toward one of the parties I organized. I would've rather they just not go if that's what they thought.