Any car will need tires, brakes, oil changes, and tune-ups. So other than the transmission problem at 90,000 miles, your car is typical.
90,000 miles isn’t bad either. Unless it’s a major inconvenience to service your car once in a while, I’d say replace the transmission and keep on driving it. Maintaining the Saturn is pretty much guaranteed to be cheaper than buying a new car.
You might want to get a second opinion on the transmission too. Maybe it just needs a new transmission filter and new fluid…