In all likelihood the new owner would want the account to engage in some sort of massive scam;
No doubt, as I can't see anybody trying to buy an old account simply to enter it into a signature campaign and then wait until the buyer earns enough to make the purchase worth it--idiots who buy accounts here generally aren't that forward-looking to begin with, so there would have to be some kind of scheme they had in mind to scam $10k+.
As to what sort of account would be worth that amount of dough....it'd have to be an account that was very trusted, Legendary, and even then $10,000 is a
lot for a single bitcointalk account, especially with all the risk involved in getting caught. Hopefully none of the OGs here would consider selling their accounts to a potential scammer (or anyone else for that matter). Bad things happen when accounts change hands.