It really depends on your skills and enthusiasm. Long ago I used to buy old cars based on passion and excitement, and frequently regretted it later. It's often better to wait and buy something in better shape to begin with. It can save countless hours and wasted dollars. With the rust that is showing there is likely a great deal more down in the floors, cab corners, and rockers. But the worst part for me is the roof itself. Expanding the photos 200%, it seems the roof panel has been used for a trampoline. Replacing a roof requires more welding skills than I possess, and once the lid is off it may become obvious far more repairs are needed to the inner skin as well.
Welcome to the forum regardless whether you buy this truck or not!