I posted this one on CL after playing with it for a while for $100 firm. I had maybe $50 into it. It had plenty of hits and sold the first night for my asking price. The guy loved it. Probably could've gotten a little more but I usually price my cheap bikes below market and FIRM, and then watch 'em sell quick.
So, I'd say depending on where you are there could be a market, but you aren't going to get rich. That doesn't mean it can't still be fun and mildly profitable. Especially if you already have a cheap source for bikes and parts.