Prices vary widely, mainly by condition of truck but also in how scarce in any given area. I paid $6300 for mine in Springfield, IL. A lot for me, but not when considered for what I got. I got basically a turnkey vehicle recently out of the IL National Guard, the only defects were no spare tire and the sprag wasn't working in forward. A kit from Memphis Equipment and a lot of free advice from the MV list too care of that.
I had been shopping for around 10 years in all markets in the Midwest. I looked at a lot of guts and feathers(stripped vehicles that you couldn't tell they were dump trucks if the paperwork didn't say so) down at Ft Lost in the Woods. Privately owned vehicles already reworked where way out of my price range. After I made the plunge dump trucks started showing up on GSA for around $2K. Most were fire and forestry turnins but still good deals.
Patience pays.