Account selling is not prohibited but it's discouraged. I don't think this thread also belongs to Meta since you're already posted "Scam accusation" board too.
Why are you sold your reputation in the forum for just 250$ in the first place? I also Agreed with "Pharmacist" there's nothing to this matter with other members.
Got any proof that you tried to sell the account? It certainly looks like it, based on the password and e-mail change but I'd like to see PMs or whatever you have before tagging the account.
I think seller also to be tagged. Why only buyers?