I read somewhere that the four cylinder engine is actually more durable and trouble-free than the M50/52 six, which is saying quite a lot. In any event, reaching 300,000 miles and more with a properly maintained, non-abused engine is not only possible, but within expectation. Do check to see if the camshaft seal has been replaced though, I think there was a problem with leakage and there was a "silent" recall to remedy that. The front ball joints/control arms are a perennial weakness with these cars, so those might have to be done (not all that expensive), and given the age, the rear trailing arm bushings might also be due (again, not all that costly). Check for body damage and corrosion, not only of body panels but also brake and fuel lines. Steering should be okay, but as the power steering fluid has no drain, check the level and the cleanliness of the stuff. Radiator, hoses also. If the car has an automatic transmission, I've heard that they can get kinda balky at about the 140,000 mile or so, but maybe less so with the 4 cylinder than the 6s, with more torque. The alternator might also be at about the overhaul stage. "O" rings and other connectors might need replacement on the a/c system. If the car's in decent shape, and especially if you have service records, the $2800 isn't bad, but of course haggle.