World of Warcraft Murloc pet worth over $500?

At Blizzcon 2005 Blizzard gave out a special code to each attendee so they can get their very own baby Murloc pet. What does this special pet do? It shouts the trademark phrase "Grrrrmalrrrrgrrahhhh" and dances on screen. The card is also valid for bringing a player into a beta test. One person believes they can sell the pet for at least $500 and up to $800 on eBay. Instead of spending cash to see the special Murloc dance, you can check past the jump to watch an animation of Murky the Murloc.