If you're serious about buying an older car, stay away from the classic care dealers, unless you're will to part with far more money that is necessary.
For example when I was looking to by my 72 Dart, I found a couple at antique sealers and classic car dealers, both of whom believed the cars were made of platinum. Many private sellers believe that to be the case, also.
People will sell pure junk and put a ridiculous price on it, and some idiot will come along a pay it. Still, your best be is usually a private seller. Someone you can talk with who isn't relying on the car to cover his next paycheck.
There are some really decent cars that don't need a ton of work for some pretty good prices. Shop around, do your homework, don't be afraid to counter offer, and don't be afraid to walk away if the price isn't right for you, or if you have any reservations about the deal, the car, or the seller.