No trade, no sale, no purchase or merchanting is safe right now.
The rather crewel truth of things is, if anybody who ever handled meso purchased from an illegal source buys, sells, trades, or even drops one, the new person who took part in it is also flagged.
People 3, 4, 5, even 10 steps out from the initial purchase have been flagged and banned.
This is not a sane practice, it is merely a legal one.
Though it does kill the economy completely for a long while, on the upside maker will allow you to get the items that otherwise you'd have had to buy.
The downside is grinding for stat crystal ore and your own dye.
Good luck maple, and gods forgive nexon, they know not what they do.