A hell of a lot more than $500, but it all depends on the rust situation. More pics please.

Check all these areas for rust and let us know...
Front pan
Front fender wells
Rockers
Jack pad area
A and B pillars
Windshield area by door hinges
Floor pan area
Rear seat pans
Rear shelf corner by rear window
Lower rear window corners
Torsion bar tube (rear)
Where did she spend her time? Dry climate or northern with the dreaded winter salt? Any accident damage history?
Looks like a great find. Frankly, no matter what condition she is in, 500 bucks is a friggin' steal. You could sell one wheel and get your $500 back.

That has to be the steal of the year.