Hmm, I bought this Peugeot UO8 for $50 back in Dec (well, I bought two bikes for $100, so assume $50 each):
I've since sold off the saddle, pump, brakes and levers for about $125, so I'm $75 in the black! Of course, both cotters need to be drilled out, and I'd need to replace all of those parts. And it's too big for me, but that all sounds in keeping with the Clunker Challenge vibe.