At that mileage only real engine issues will be valve cover gasket($50) oil pan gasket ($40)maybe rear main seal ($20) and possibly the crank position sensor ($90). Also if you are doing the oil pan do the rear seal its a 2 piece seal so you don't have to drop the trans. Aside from that if there is no rust issues it should be good to go. Also would personally look at a hardtop, soft tops just beg to cut up and broken into. Also if I were to sell my XJ I would look at a LJ (extended bed TJ) rubicon, with a 6 spd. You will pay a little more as yet are less common but the longer wheelbase helps with the Jeepiness of the ride.