Why not to do well in the game

[Kallera]

They attempt to algorithmically flag RMT accounts for suspicious activity, and RMTs alter tactics to dodge. It's your standard cat-and-mouse stuff, and that's why SE is not keen on providing details about the specific methods. Once SE have an RMT flagged, they can link to buyers through logs and remove buyer gil. Once you get a step beyond that and the gil has filtered back into the economy through gil-buyer purchases, it's hard to even justify trying to do anything with it. When I put something up on the market for 300k (composed of 200k worth of mats), I can't control who buys it.

I don't remember "putting item up at the auction house for high prices." Being something that is against the terms of service.