StevenY has one, I know that. He's got it signed by several of the actors.
It comes down to whether or not you really want it I think.
If it makes you happy, then get it! If its not something you feel strongly about then don't.
I always find I regret more not doing a thing then having done.
I have a mask from the guy on ebay Brian Hova
The quality is great! I'd say it's a 80 percent accurate replca but that's only my opinion.
I paid $185 for it so I think the price was good, I've seen them sell for $500+
let me add that the mask looks more realistic in person than on camera!