A great deal of the pricing is going to depend on the condition. It is over 30 years old, so price guides are all over the place, and I believe you have the right idea asking actual owners. That said, at that mileage, there are likely wear items that may need to be replaced if they haven't been recently. My own 1990 has been pretty much trouble free, but I fiddle with and modify so not a good source as a preservationist. Your own mechanical skill will determine how costly it may be to tidy the car. At first blush, the asking price seems high, but without knowing lots of details and examining the car, that isn't a fair assesment. Where is the car located and where has it spent its life?