WTH?!

It took me from start of v1.0 till 2 weeks ago to get all my crafting classes to 50 and this player can do that faster than I'm able to finish 1 synth?!

I hope you did report that player and I really hope SE will ban them fast.
But the problem is that the damage is already done as soon as these players flood the market with crafted stuff and I doubt it will be possible to retrack everything they do. They farm the mats 24/7 with bots and now they level classes in minutes instead of weeks or months.
I guess what they do is craft high level gear and use other chars to turn them into materia to sell and get gil which they can sell for real money.

SE really has to find a way to prevent all this hacking and botting.