Birthday party planner

I have spent the majority of my day on the phone trying to find a decently affordable place to have Olivias birthday party. She wants to invite her whole class, which is fine, except I don't really want to have to find a way to entertain 15 children in my house for two hours. Especially since most of the kids dont know her and I don't know any of them. I suppose this would be an exceptional way to meet the parents of the kids she will going to school with, but family alone fills a room and with 15 kids it could make for an interesting party. Needless to say kids birthday parties are not cheap, at all. Seriously most local places want at least 8 - 10 dollars per child. With 15 kids that a lot of money for a few hours of fun. So being the procrastinator that I am it is now getting down to the wire and have no where to go, which means I suppose I should start looking up some really great kids party games.