I can't say if it's good or not, but here's what I do know from my personal experience with an old Ebay bike...

I got my bf a vintage 1960s Coppi complete bike. The frame was in perfect condition, no rust, actually looked like it had never been ridden. He decided to put skinny tires on it, ended up switching both deraillieurs, and got it a new crankset, seat post and pedals. By the end, we ended up spending close to $500 on parts and labor, most of which were vintage, or at least used. I got the complete bike for around $150.

It adds up fast. I also want to add he LOVES this bike, so it was worth every penny.