I wouldn't sell a bike in that condition. If I couldn't make it better, I'd either pitch the frame, and keep the parts for the next project, or give it away to someone who wanted to tinker on it. If you want to recoup your $20 investment, keep, or resell any parts you like.

edit: or just ride it or sell it for the $ I've got in it if it's rideable, but I wouldn't consider that gearing practical, so that rules out cheap practical transportation.