used to be able to pick up Double bubble "builders" for a decent price a while back, but not anymore. Basket case cars go for $50,000 now. all the more desirable small Italian cars have gone nuts on prices the past few years. I just painted a 1960 Alfa Spider Veloce that is undergoing a top notch restoration. they will likely get 6 figures for it at auction this Spring. check out the asking price for this one on Craig's list
http://sfbay.craigslist.org/pen/cto/2821072768.html
About these small vintage rear engine Fiat based cars. I own an Abarth Allemano Coupe that I did a full restoration on years ago. the amount of work (and money) needed to bring these lightly built antique little wonders back can be staggering. you can sink 1000 hours into these cars.