wouldnt that effectively make it so only people as rich as mephisto would be able to convert their gold to platinum and still be able to buy whatever they want? I personally wouldnt be able to buy anything worthwhile for a very long time :P but then again it WOULD drain their available funds eventually unless they could profit enough to sustain the conversion penalty.
I feel like if anything keeping gold untradable while still implementing the other subscription features would be the best way to go. Even though i would really like to be able to sell items for gold more easily so I can get some gold stockpiled haha. But either way Ill manage and so will you guys.