RMT is not illegal in that you won't go to prison for it, but it is against the rules. Everybody caught doing it gets banned. Trust me, the GMs get real evidence there was an RMT happening between 2 people, they both get shitcanned. Remember 'legal' is whatever the GMs say is legal. It says so in that blanket "we can do whatever we want to your account and you can't do shit about it" ToS clause.
But let's face it, just like it takes at least 2 to argue, it takes at least 2 to RMT. Without a seller AND a buyer, there ain't no RMT. Both have to be willing to break the rules so it is just as bad for the buyer as it is for the seller. The fact that somebody got scammed in the middle of it is again, solely because both parties were hot to break the rules. The fact that the seller is a douchebag is irrelerant. You don't wanna get scammed, don't RMT. Simple.
Why was somebody dumb enough to buy a banned account? Especially if they can't afford to buy themselves a decent monitor. Stupid people will be stupid people and are ripe suckers to be scammed. The guy that scammed him laughed all the way to the bank and is laughing even harder reading thus thread.