I remember there was an ouroboros symbol pin in this series of pins:
I let it get away YEARS ago on eBay. Man do I regret that but I did snag the only Envy pin I have seen up until tonight (the pin I got was of that same series, has his face inside a triangle, the pin I saw tonight was full-body and of a new series featuring most of the cast).
Also any jewelry of the ouroboros. Really, anything. I love the design and am hopeless in my obsession (some of you may remember all the fanarts and crafts I create with it). I'd prefer to barter/trade but am totally willing to pay too! Just let me know what you have and show me pics. :)