I have been talking about this for a long time with my LS friends. I completely agree that this could work very well. I really see no downside to the idea. If someone plays a lot and has extra Gil they could buy a free month of game time and if someone really can't find the time to grind gil they can just buy it directly from SE with no chance of being banned.

The way I see it everyone wins. As for RMT's selling the currency that gives 30 days of playtime. If they bought up all the currency in game and someone could then buy a 30 day sub for less than the monthly sub cost why would that be a bad thing?