[Landseer]

Past service and repair sounds reasonable to me. Price on high side, but not the worst we've heard of, especially if electrical sensors and rubber was changed in intake area.
(McLean VA P dealer reportedly charged a rennlister over 10,000 for a routine TB replacement a few years ago). Car might be fine. Then again, if 30,000 miles and more than 4 years ago, car is approaching next TB/WP service intermal. Reciept would be helpful. Fuel lines need to have been replaced. Very important.

Water pump seizing, and/or other pathway rollers and guides becoming damaged, are the paths to timing belt failure. Same for 944/951.

89 automatic has best gearing ratios. Fun car.

Intermittent electrical issues can emerge. Suspension work / shocks can cost more than typical cars. Cleaning grounds and keeping interior dry are key.

If exterior is straight and car is original paint, interior is clean and car was garaged, not used in winter, then those things are big plusses.

They are hands on cars. Hobby cars. Old cars. It can get out of control a couple ways. You kind of have to be all-in, part of the hobby, else, with deep pockets and a good relationship with a 928 specfic mechanic.