"I've only recently reached level 60 and have been actively farming epic dungeons for purples, I'm somewhat dismayed and would hate to see how much of those hard earned purple geared I've lost dur to the rollback." You'll lose the same amount of spent playtime as a level 1 character.
How would a rollback cost them Zen transactions? They could simply refund the zen back into the player's account for any purchases made with it, and they could spend it again.