I picked up a 2 door post '70 Road Runner for $3k out of Orem, which seemed pretty reasonable to me despite being a shell. I've also seen some big stashes of old cars off US 50 between I70 and I15. There are also another stash or two off I80 just over the Wyoming line.
Granted, I've never tried to see if any of them would be willing to let go of cars or parts and at what cost. I'm just thinking they are out there somewhere if you start shaking the tree.