Many years ago, I bought a complete set for my '68 F250 Highboy from a junkyard. They were brand new and they had probably a hundred of them in stock because they were so popular at the time. Not sure if they are still available, or if this info is of any help, but you might try calling a few yards just to see. They cost me $25 each back then, but that was 24 years ago. I've still got them, but I need to keep them because I still have the truck...although it's parked for good. I don't have anything to replace them with.
By the way, they are lug-centric, not hub.