Personally, I think trading would be my favorite way to get rid of Sanderson swag I didn't want (if I were getting the swag; I'm too broke for.) I like the idea of trading because then people can give what they don't want to someone who does want it, and get what they do want that the other person doesn't want (as much as what they would get). Shipping costs could probably be split 50/50 or any other way both parties agree on.
Then again, my family is so focused on trading that we trade lots of our stuff amongst ourselves, including (especially) Christmas candy.