Having owned our 99 Cherokee since it was new, I would not be afraid of the one that is listed in that ad, just inspect it well.
Our is at 215,000 miles and is just now beginning to need the wear items replaced that should have worn out at 50,000 to 100,000 miles. Being in PA you need to inspect VERY closely for rust.
Most expensive repair to ours is, I put on a new exhaust manifold myself. That was about a four hour job but I went slow. Ours still has the factory muffler, starter, PS pump (although steering is getting stiff), AC compressor, water pump, thermostat....
I had the brushes replaced in the alterantor for about $40. I think I will soon need new front unit bearings. Engine does not use a drop of oil. Transmission has never needed work. On the other side of the coin any vehicle can be a dog if not taken care of. 99% of all the work needed to our Cherokee has been to normal wear items, and those all lasted far longer than they should have. The luck we have had with our Cherokee was a big factor in our decision to get a TJ also.
I might add that you will miss the TJ. Our TJ is flat out Jeep Fun. The Cherokee is just another vehicle (a good one but the TJ feeling is not there).
06 Solar Yellow TJ X obtained 10-2009 with 3400 miles
99 Cherokee Sport, bought new, now @ 223,000 miles