It's a variant figure that was up on several auctions on ebay and it's also being sold through AOW. Just because it's a variant doesn't mean it's rare. Judging from the price, if it was truly rare, it would be more like 120 dollars, not what they're asking for.
It's more difficult to get than a regular figure.That makes it harder to find,more "rare" if you will.But,of course,some items are much more difficult to find,which make them even more rare.