I cannot believe that the ZombiU bundle goes for $700.00 on eBay now!!!
Another explenation: Sellers raise prices to something nobody would pay when they are low on stock or don't have that item in stock anymore to avoid to put it up on eBay again. The price will go down once they get new stock. This case happens on ebay.de frequently for eShop cards. I don't know if it's the case here, but it might be.