It's hard to value after a major change in the game. I'm US and so I know it can be different but before the Shattering I'd value this thing at like 20-30k and maybe more. Now I'm not sure how it stacks up so I'd value it much lower. It's still to be determined what the demand and supply will be like as well. In short, I'd sit on it a bit until things calm down.
I bought mine like 3 months ago max for 12k (EU).. waited for this hat to appear on AH for about year and half. Its rotting in my bank unbound now and Im quite happy to finally just have this item