Selling Freehold powerleveling runs at 20k per level (about 4.5 levels per hour)! Heirlooms are not required but recommended (30k per level without heirlooms). There is also the xp gem and commendation potion that are available to speed the process even faster.
If you have any questions or are interested feel free to reach me in-game at Existstofarm-Whisperwind or Myshamonna-Whisperwind. Or add me on battle tag Shamonna#11386.