T.N.
R., if you are pooling your money, I would suggest the best well-spent money would be on renting an inflatable "jumpy castle" type thing. Or, even for $200, you can get your own inflatable jumper that you can keep and it would be a more scaled down version for littler kids. We got one last year and we can even use it downstairs in the winter! (try this link: http://www.toysrus.com/product/index.jsp?productId=2332961 )
It will keep the kids and their friends busy for hours. For that same amount, you can entertain them with a magician - but only for a while. Hire a high school kid to do the face painting. You can do that for very inexpensively. It doesn't matter if its phenomenal - it just has to be cute.