Good places to find Golden/Silver age comics for cheap?

Anybody have any ideas or stories about how they found some golden/silver age comics for pretty cheap? I live in the San Diego area and was curious if anyone has some good strategies for finding these gems.

Good luck with that, I remember there is a website online that does exclusively golden age comics that no longer have a copyright owner. It's mostly filled with Western stories though with very few actual superheroes, so I doubt it's what you are looking for.