Also, it's what you DON'T see in these pictures that you really need to look at.
Frame, underbody/floor pans/trunk pan, common rust repair areas at the rear of the front fenders (right in front of the door opening), rear quarter lowers behind the wheel openings, and the windshield base, among other areas.
Convertibles often have rotten floor pans and quarter inner/wheelhouse inner problems. Does it have a power top and does it work?
As far as the body goes, look for consistent gaps and evidence of old (or poorly done) repairs.
I agree with Bear...$25K seems steep for what you can see, unless that turns out to be the original engine and the frame/floors/underbody are super clean.
1968 Pontiac GTO
1983 Pontiac Bonneville (G) wagon
2008 Pontiac G8 base