pictures, pictures, pictures.
a complete rust free car could easily be 5K or more, but "ohio rust free" is not "so cal rust free" and some people's definitions of rust free, been sitting and needs gone thru can vary wildly to say the least.
if this is your first go around with a-bodies, link up with somebody who has indepth knowledge about the problem spots on these cars. some times things that look good can have a ton of hidden problems that people who don't have a ton of knowledge about would totally miss.
or do a whole bunch of research before buying.