Good bike. Need a lot of work though. Are you going to do this work yourself or pay someone to do it? If the latter, I'd get something more ready-to-ride from the start since this will cost $100-200 to have a shop go through it and get it road worthy again.

If you're doing the work yourself it's a great buy. You will not find anything in the $20 range. Before you buy, have the seller prove that the seatpost and stem are not stuck.