300 dollars will get you a complete fixed gear bike at bikesdirect.com
http://bikesdirect.com/products/windsor/thehour.htm
sort of takes away the fun of what you want to do, but maybe you can just take the wheels off of these guys and then use the frameset for your own project?
there seem to be a pretty good selection of track/ss wheelsets for sale on ebay. if your friends aren't too concerned with having the best or the fastest, i see no reason why they couldn't make good use of some of the utilitarian listings.