2011 Casacius error coin

[casaciuserrorcoin]

Hey everybody!
Long time reader but first time posting. I was wondering if maybe anyone could help with my query (Mods please feel free to move if wrong area), I have a 2011 Casacius error coin (Missprint) unopened, I was wondering what you guys think of opening the coin and selling the BTC? would you recommend selling the coin as a whole? and if so the best place one might sell it and current market value? any advice is much appreciated!