I believe a good way to help take gold out of the system would be having an in game option to be able to convert gold into EP. So HCS are ahead, make the conversation rate greater then the current EP to gold ratio which is 10/1. Have your conversation rate at something like 1.5 to 2g for 10EP.
This will help pure F2P users get much needed items like sacks, will give them more reason to play and grind gold as they can get the vanity sets themselves without going through a third party and will help remove the stigma that you have to pay to win. Of course you don't have to pay to win but any game with a cash shop holds such a stereotype.
It's good for the game, good for the company and good for the player.