We already have something not unlike this in time cards. For it to work as an in-game item, though, would have required it's presence in the game from the beginning. Eve's model works because it was there from the beginning, it was one of the game's selling points to get players into the game. If they were to introduce that in the game now it would be so overpriced as to be out of reach of those that'd use it. Then there's the RMT. The reason RMT never took off on Eve is the game's other core mechanic, open world PvP. Because the markets are local and almost everything is an item if you wanted to sell your time tokens you had to 'physically' move it to market. But between the hub systems there's areas where pvp can go unpenalized making moving something like time tokens a high risk endeavor. There's no such risk here. I can buy an HQ piece of high demand armor, travel from Gridania to Limsa Lominsa and noone would be the wiser. RMT could easily start selling time tokens, real or scam.