CKDC - I'd replace the hinges or repin them. All four doors on my crewcab started sagging after a while (the drivers door being the worst as it's used most often). Simple to do - hammer out the old pin, install new bushines and hammer in the new pin and it's done. Bolt door back onto hinges or bolt door and hinges back onto cab, depending how you took it apart.

Dehamma - prices for used parts vary wildly based on condition, location, the yard itself, the yard owners mood, etc. One yard by me in NJ for example wants $75 a door, with glass and anything attached to the door. That's not unreasonable if the glass is in good shape, the window/latch mechanisms work, and the mirror on the outside is intact. If not, find another door (or several) with good bits and combine them to make a door worth $75

A yard out in PA I go to once in a blue moon wants $35 for a complete door. So it varies.