First of all, there's no report button. Just a blacklist which I'm assuming is /ignore. I use blacklist for annoyances, not just gold spammers.
Secondly, theres no ignore option when you click the spammers name. You have to type out every ridiculous concoction that the sellers come up with.
Thirdly, if you use a ps3, which I do, typing is a nightmare.
I may be off here, but it really seems like you are encouraging the in game gold selling. You guys getting a piece of that pie since you're still p2p? Please enlighten us as to why you seem to leave out basic spam prevention that's included in every decent MMO out there....