Why? It's not against the rules to sell accounts. There is a black market section here, but it doesn't include a Grand Chase section. Posting this here attracts people who may want to purchase my account.
I don't think you need to close this just because of that reason, someone might want that account eventually. But in the other hand... Isn't this site meant for cheating? :/. You might want to do a video of your character in youtube and sell there to someone ^^''