So thats it. I did it managed to way long enough and to get enough gold to unlock it on the first day.
Access to wings may be purchased using in-game gold or real world currency. Wings can be purchased individually for 700 gold or $6.99 USD. Players can earn the in-game gold needed to unlock the next wing by completing various quests or emerging victorious from the Arena—or they can choose to unlock the next available Blackrock Mountain wing using real money.