I have never seen these trade for a premium over the actual value of the coin in the slab. Im sure there are some people that collect these? Have you ever seen them sell higher than the coin in the slab due to the error?
With almost every bulk order I send to PCGS, one coin comes back mislabeled. It totally screws with my accounting for the submission until I find it, too. While nobody I know has ever wanted these relabeled, I also don't know anybody who would pay a premium for these, although there's probably someone.
I can't see paying a premium for an administrative error. They're interesting, but I'd rather spend my $$$ on what's inside.