Suppose this system goes online, I'm curious about its real effect.
(1) What is to stop RMT vendors controlling the prices on market boards? They do have a huge supply of gil.
(2) What happens if the RMT vendors just bot more, hack more, cheat more, use that "free" gil they got to buy up time cards, and sell them for real world money cheaper than Square Enix?
Mog Station - USD$12.99 per card, 1 month game time
RMT Vendor - USD$10.99 per card
Note that now they are actually selling game time which they bought with botted gil, i.e. Square Enix has let go of its monopoly on game time. It's even more profitable than selling fluctuating gil because game time has a official price tag. You just have to be slightly cheaper. Since the gil they use to buy up these cards cost only their bot subscription fees (or are stolen), they have a lot of wriggle room.
In effect, they become an officially sanctioned reseller of game time. And in order to be more profitable, they put out more bots, advertise harder in game, and they will also advertise for buying/selling the time cards in-game and there would be nothing anyone could do about it, because it is a legitimate tradeable game item.
What's to stop them spamming harder and longer than ever, now that they're actually trading something sanctioned by Square Enix?