In an ideal world account sales just would be banned. However, I'm not sure how it would be enforced in all honesty. At the moment they are communicating through the forum, but if it gets banned then its just going to go to external sites. Maybe, that wouldn't be so bad? I guess then though account recoveries could be even more problematic than they are now.
Recoveries are nearly-non-existent now so can't be much worse, can it?
If you mean recovering an account by a seller after it's been sold - the solution is simple: don't buy accounts, or at least don't buy from untrustworthy sleazebags. As long as legitimate recoveries are functional and account sales are officially banned there shouldn't be any tears shed for account buyers swindled on some other sites.
But I don't think banning accounts sales would solve the real problem, which has more to do with why those sales exist.