Easier reporting would certainly go a long way to making the process a lot more smooth. Their current report system is ridiculously inconvenient and laughable. The sort of thing you'd learn in an entry level ICS course.
In-game GMs are great for that purpose, but not very feasible in most cases. The ban hammer in-game has its own protocol to follow, which involves a lot of "are we sure X is doing Y?" sort of thing. Ridiculous, definitely, but standard practice. It's exactly why a lot of "legit" players that bot their levels never get caught for doing it. Having a round-the-clock in-game GM (ideally having 2-3 per server) is a lot of employment related flags to raise, thus the not very feasible part, as it's not just NA/EU, but also JP... probably even China.
The market already exists, so the banning of buyers, while meaningful to some extent, does not curb the presence of RMT. It's an established business, so them being on any given MMORPG is inevitable, one being profitable or not. In most cases, they're not even spending their own money on subscriptions.
In this game, it really just comes down to the optional chat filters that many of us have been asking for since day 1. It is literally the end-all, be-all of stopping or minimizing RMT advertising, which is the way we experience RMT presence the most.
