I got mine off of craigslist for a song. There is a catch though, you have to be pretty patient for deals and you have to be very picky about quality. The guy I got my stuff from just moved here and didn't want to unpack it. He had pictures of it and it was in really good shape. I couldn't be happier, but man it took me probably 3 months to score it.
Play It Again Sports (if you have those in your area) is also a great place. Short of that, the usual sporting goods store will do.