Yesterday afternoon, a copy of the Spectral Tiger card from the WoW TCG sold on eBay for the astonishing price of $2000 (the starting bid was $100). Why so much? Well, for one thing, it's a loot card -- it gives you access, via a scratch-off code, to an in-game mount that you can't get any other way, called (surprise) the Spectral Tiger. It's available in both normal (60%) and epic (100%) speed, and it looks pretty sweet.
Furthermore, the TCG set of which it is a part, Fires of Outland, has not been released yet; it debuts on August 22nd. This card was apparently obtained at pre-release event. Still, two grand is a lot of money; that would buy you over 11 years of game time, or (in my preferred money visualization scheme) 150 pounds of really good coffee.
We gave away this very same mount not long ago (don't say WoW Insider never gave you anything) -- a $2000 value, apparently! But if you're not our lucky winner, and you simply must have a translucent cat to ride on, there are still a few more going on eBay.
[thanks, Jacckk of Perenolde]