If dealer service at correct intervals, that truck, esp. since it's a 2001, has a Lot of life left. Just make sure you have a new rad or external trans cooler installed. If you don't know about 'strawberry milkshake', search on it or read the 3G Buyer's guide in the stickies. Read that anyway, if you haven't.
Just curious--timing belt interval is 90k. Have they done two, as it is past due for the second? The dealer will charge ≈$1000 for this job and you should do water pump, idlers, drive belts and some other stuff at the same time. Just so you know....certainly good to bring up when haggling if it has not been done.
Kind of wondering if this is why it's for sale.