I wonder if FF14 could eventually add a system similar to the CREDD from WildStar, the PLEX from EVE Online, and the WoW Token from World of Warcraft. Such a system could work like this:

A player who wants more gil could buy a token for $20 on the Mog Station, and it would be delivered to a single character. That token could them be posted on the Market Board to be sold for gil. The exact amount of gil would depend on the market value at the time.

Afterward, another player would buy the token, and when using it, would be presented with an option to either add 30 days of subscription time, or to add 1500 Crysta which can be spent on Mog Station items or services, new FF14 expansions, or other Square Enix games.

This would allow players who want to buy gil to do so through a safe, secure, and legitimate official channel, allow players with excess gil to stay subscribed and buy more Square Enix games without spending their own real money, and completely cut shady gold seller sites out of the equation.