I did this sort of repair to the body in a backyard fashion. No tools, and the technique involves zero bending and forming of metal, its all done with 18 guage sheet metal, which naturally forms during the process...
The truck is worth 500-850 imo. He will probably take it, there isn't much time left on the body.
You can repair it like this for around $100:
http://www.toyota-4runner.org/classic-t4rs/170887-89fourrunners-rust-repair-progress-thread.html
It has been two years and two winters and it has held up stupidly well. I just posted a pic a few days ago in the 1st gen picture thread.
That is a super cheap, no tools, easy backyard repair for those of us who just do not think it is worth investing! Haha.
I am just saying, if you grab the 4runner for $500-$750, and you plan to wheel it and arent too concerned - cheap option.
I don't think I would buy this one to fully restore with expensive body work.
So many nicer ones out there.