3/4 tons aren't worth as much as 1/2 tons. Of course, condition is everything. A running 3/4 ton AD with some rust, but still a reasonably solid truck is in the $500-1,000 dollar range. Not a lot of people want the 3/4 ton due to the low gears and rough ride, but they do make a heck of a work truck.
Saw a guy with a 54 3/4 ton for sale at a show recently. Truck needed rust repair, paint, bed wood, and burnt oil. He was asking $2,500. No one was even looking at it, he was so far off on his price.