What about a trade depot or storefront...like a list that anyone can post a public swap and anyone else can look, like a storefront to all badges for "sale" on the public swap, doesn't matter who owns them currently...and the trick is that anyone can automatically swap badges 1 for 1 with any of them on the storefront? So like I add any badges to the public storefront list that I have available, anyone can take one as long as they give me one back. I think like the extra card in Catan, that is available for anyone to swap at any time, just give up one you don't want and take one you do?
From Dr. Phlox: