I honestly don't know. They don't seem to forbid it on the BLM permit website and considering they charge $30 for refunds on the permit it seems more likely that people that can't make the trip would want to sell their permits rather than get a refund.

I am hitting Aravaipa this weekend and a friend wants to go, but unfortunately there are no permits left for the weekend. I have a permit for Saturday or Sunday, and was posting to see if anybody is unable to go and would be willing to sell their permit so my buddy can go.

Thanks,
Chase