What is considered high mileage? 250k plus isn't uncommon for a Jeep.
My 00 WJ has 165+ on the clock. I have the 4.0L and it is still going strong.
**If** I keep this vehicle (I'm thinking I want a truck), I'll have the transmission rebuilt as I use this Jeep as a tow rig and don't want it dying on me in B.F.E.,. While the transmission is out, I'll replace the chain in the transfer case. I will also make an access hole in the spare tire hole so that changing a fuel pump is an easy job whenever, and where ever that job needs to be done. I might just replace the fuel pump before I have problems, then carry the old pump as a spare. I already replced the AC Evap, heater core, water pump, radiator, electric rad cooling fan, the fan relay, CV axle shafts, front driveshaft, and the Crankshaft Sensor. The ball joints will also be inspected (my WJ is totally stock).