IMHO it's a fake. The wire have no trace of any wear/stuffing. Read my post above. It's just my opinion OK. The lid itself hardly show any marks of wear as well. Paying 12K for a M40 with chicken wire is very strange indeed. Each to his own, but i doubt it sold for that.
I think this is an original helmet, and due to the rarity the price is not that surprising. High end desirable helmets such as this can reach untold heights. It all depends on what somebody is willing to pay.
Wire + camo , sure they exist. But what makes this one a solid 12K worth , surely it is a documented vet pick-up or something or someone just wrecked the auction. For that money I'll buy myself a nice textbook unquestionable DD SS helmet.
I've rarely encountered many people who are willing to pay what something is really worth (I have 10 yrs on eBay selling stuff, still with 100% feedback, I may ad (pun intended ;-), nevermind people who are willing to pay more than something is worth, or infinitely more than something is worth, but I wish I could find a few ;-)