wowgoldgate has a nice and active staff, they do what they say they do and are legitimate enough for me.
Website
Powerleveling
Account Safety
Your character is leveled by a master player that conducts himself in an ethical manner in the game. Without any advantage over other players.
Account Security
They are only requesting Account Name / Password for powerleveling.
Character Progress Tracking
They let you specify hours when you want to play.
Coupon code if you're going to purchase there: mmorpg
Regular price per 1000 Gold: $14.80
CD-key's cost $30.99 and are US only.
Once your order is approved, a mail will be sent, containing a screenshot of the CD Key.