Here, the closest junkyards are a ripoff. A couple of years back it cost more for a used 14" steelie for a saturn from one than a new one.
Check car-part.com if you haven't already. Not sure how much will show up but it's worth a shot. Sounds like there's a good chance you'll end up buying tires too, buying online someplace and getting the free mounting, possibly free shipping could end up being worth it plus less hassle.
Personally, I paid $325 shipped for factory take offs for a Chevy Cruze last November. That included wheels, lug nuts, wheels covers and TPMS.
A few months ago I drove 4 hours round trip and paid $100 for Cobalt (steel) wheels with Kelly snow tires (8/32nds) on them. In hindsight, not really sure it was worth it with the driving but it was a good excuse to go to a restaurant we used to frequent and had not in years.
Much different examples then your truck though I think.