SE did it to themselves. Anytime you make crafting a major part of the game, you open yourself up to this level of RMT.

I would say it is not fixable by anything less than extreme measures.

If you made gil borderline worthless in game, RMT would be a non factor.

People want to EARN their house, relic and gear and it is a shame that SE is encouraging people to BUY their house, relic and gear rather than earn them.

Anytime people feel that they can buy a resource many many times easier than they can earn it themselves, your entire game design is flawed.

Even people who work at Mcdonalds for a living can buy gil cheaper than they can earn it, unless they do DOH/DOL as the main aspect of their game.

And you really expect people who make 50k+ a year to spend hours farming tiny amounts of gil? Stupid.

I do not buy gil out of principle, but if I did not have a decent amount from 1.0 there is no way I would have my relics and the ability to teleport around as I please.

Make every single thing in the game that costs gil consumables, vanity, convenience or luxury items and you will NEVER have RMT problems to this extent.