If I found a good vintage bike at a great price, and I knew what it was, and I knew enough about the hardware that I could tell if parts were original, cobbled together, worn or pristine, or decent aftermarket, and I was a good mechanic on old stuff and had the specialized tools to work on it, then I'd be all over that deal.

If with a limited budget I just needed a decent bike for transportation that I could get on and ride, that wouldn't have problems and wouldn't need much spent for fixing it up, I'd go to an online source. Bikes direct, Nashbar, Bike Island, even Amazon. Reserve $50 or so for the helmet, patch kit etc.