Its illegal to sell your WoW account (because its not yours)
Notwithstanding anything to the contrary herein, you acknowledge and agree that you shall have no ownership or other property interest in the Account, and you further acknowledge and agree that all rights in and to the Account are and shall forever be owned by and inure to the benefit of Blizzard.

http://www.worldofwarcraft.com/legal/termsofuse.html
Read Section 3.