Years ago I had a 1970 F350 flat/stake bed truck.
I wanted to convert it to a dump truck.
Bought a dump frame off an F600 from a junk yard. It was one of the old types with pump, cylinder, reservoir, and control valve all-in-one on the frame. All I had to do was hook up a PTO shaft to run the pump. The PTO shaft was the most expensive part of all this. It was about $185. My transmission was an NP435. The PTO kit was about $130. Came with gearbox and cable shifter and all gaskets and mounting hardware. This was in 1989. I don't remember the brand or any details about the kit. Other than the gearbox was blue. I got it from Crutchfield Equipment in Chattanooga. I think he gave it to me at cost.
Don't know that any of this relevant almost 20 years later. But I would think $250 tops.
Back at the time, the Ford dealership would install a PTO gear and pump unit all-in-one for $1000.
Hope this info helps some.