I am very strongly considering a very nice, seemingly well cared-for 87 Targa with around 60K miles and lots of service records. It appears to be in excellent condition. I have two questions, however. First, assuming that the car does well in a PPI and there are no significant mechanical issues, what's a good ballpark price to pay for it? Secondly, the car has cloth and leather seats, which I see the wisdom of in the hot summer months but which are quite unattractive. What's the conventional wisdom, if any, on partial leather seats like this? Leave 'em alone? Replace with full leather?

Thanks a lot.