I agree.

Co-ops are thrift stores for bikes. I wouldn't expect to find anything nice. It literally is the stuff that no one wants but they won't throw in the trash. There are gems, but few and far between. Craigslist is a better source of good/great used gear for cheap. Plus you can browse CL from your couch or smart phone.

Just as yummy says, if you want to build a beater, then you can do it at a co-op for sure.