I say do it if you an do all the labor yourself.

With that many miles that SUV should be worth very little; don't get me wrong that is great for ppl like us.
Get the price down as far as possible and then go spend about a grand if u can on maintenance parts.
O2's. fuel pump. Brakes. Hoses. Bushings. Steering. Shocks. Worn out interior pieces like buttons. Etc and you'll have a good truck!