Florida, people would probably buy them here. Not much in the way of very old furniture or fixtures down here.
My main buyer for tubs was in Florida. Want to know who? His business has been off though for the past couple years, but still a kickin'.
Hmm.. shipping a claw foot cast iron tub to FL would probably run me more than $100, not sure. I often have claw foot tubs pulled from bathrooms I do rehabs on.