I have a couple of thoughts, here:
1) Anybody worth their salt will pay attention to detail. My dad used to say that any job worth doing is worth doing RIGHT.
2) I call BS on 80,000 miles. That's 2500 miles per year.
3) The tires are sticking out past the fenders. MAKE SURE THAT'S LEGAL (it's probably NOT). If it's not legal, and you have to have it inspected before you can license it, you'll have to make it legal.
4) I'm assuming (since the listing doesn't say that it's 4x4) that it's RWD. Here's what I found for value:
https://www.nadaguides.com/Cars/1988/Ford/Bronco-II/2-Door-Utility/Values
4a) based on body condition, and what others have said about the swap, I'd be inclined to consider it low retail. Bear in mind, too, that's RETAIL, as in what you would pay buying that truck from a car lot. Private sale is almost ALWAYS cheaper.
5) No paperwork for the engine rebuild? I agree with others. That's a HUGE red flag.
5a) For all you know, that engine was removed from the donor vehicle, and installed into this truck without having ANYTHING done to it. Assume that to be the case.
5b) For all you know, the body may have 80,000 miles on it, but the engine may have 900,000 miles on it.
My advice? Don't walk. RUN. AWAY.