I know a little bit about that bike. It was one of the nicer AMF bikes they had in the 70's. It has a lugged frame, three piece cranks, and center-pull brakes. Whereas most of the AMF bikes then were more like the Huffys with cheaper(heavier) one piece cranks, a plain welded frame, and cheap stamped steel side-pull brakes. Your bike is more similar to what a moderately priced Nishiki or Schwinn would have been like then. It is a decent rideable old ten-speed type bike.
You will probably want to get some new tires to replace those old dry gumwall ones and as Garage Sale Gt said try to get some fresh lubrication into the parts. Im sure you will get $80 worth of use out of it as long as it gets ridden.