Jeep cherokee '95 transmission life expectancy?

i am purchasing a '95 jeep cherokee as my first car. its a 4.0L 6cyl with 3 speed. i want to know how long i can expect the original transmission to last. curr mileage is 216K and the previous owner took very good care of it. i took it for a test ride on the freeway and it sounds good with no strange noises.