I know you said "specific" so I'm not trying to be a tool bag here. Just a general thought I guess. These tires should be free or close to it with a little bit of footwork considering you don't need anything that's functional apart from being heavy and round, so as soon as one of these heavy round things can no longer be used on a vehicle, it becomes a burden to the owner.
So, since the shops have to pay to dispose of them, they're usually happy to let you take them off their hands. I have a 50lber for dragging with a chain, and when I went to pick that up the guy walked me through his inventory of tires from small up to 350 lbs that I can take whenever I get enough room to store them.
I'm about 3 hrs from you in Aiken, SC.