That could really be a can of worms. Mike pointed out some details.
I would worry that this "cheap" pickup could turn expensive, just because if you remove the lift, then you gotta replace it with something. That may be stock parts, or maybe a shorter lift.
Even if you just consider an older basic leaf spring lift, you would need at minimum replacement leaf springs, shorter shocks, shorter rear blocks, remove tha tranny and skid pan lowering blocks, shorter or stock pitman arm...
I would start by looking at what a 5" lift kit would cost for the truck. And figure it will cost at least as much to lower it. Unless, the guy saved the old parts.
I'm thumbing thru a 4-Wheel Parts catalog; for 2000 and up Dodges, 5-6" lifts seem to be in the $1400-1700 range. Guesstimating, even for junkyard parts, you're looking at a similar price to round up stock parts.