What year/model car are you running? If it's 1986+, make sure it's a roller cam that you get, otherwise you won't see as much gain over stock.
I've been looking, too. I really like the CompCams and Crane Cams Summit has for sale (www.summitracing.com
) around $180. The thing is to find out what power band the cam is designed to support and pick the one that fits your driving style the best.