An easier way for us to report them. (That support window is slow loading all that cut'n'paste and then the nag nag nag that your support ticket has been answered).
In game GM's to catch and insta-ban.
Ban the buyers without the buyer we wouldn't have the seller.

Not many MMO's bother to do much about it the odd ones that have successfully countered RMT have used some or all of these.