I'd say go for it
. When you take care of your ride, it shows. Sure, the truck has alot of miles to look back on, but your price cap seems good enough to fund a nice overhaul and inject some more life into the truck. Any real car guy can tell you that patience, hard work [and well-thought-out funds of course!] can give a new life to any car. My 1987 FX16 GT-S was two miles from the junkyard when I bought her, but I've worked hard and budgeted and now I'd put money on her lasting another 10 or 15 years. Those first two guys were right...things wear down and go on a vehicle with that milage. But there's nothing you can't replace or rebuild.
...Not to mention all that work and time with your truck gives you experience and time away from everything else.