The only "legit" reason I can think of that would make someone say, "I'll pay you for that user account" is that they are a spammer who wants to be able to subm

The only "legit" reason I can think of that would make someone say, "I'll pay you for that user account" is that they are a spammer who wants to be able to submit links that get around the various automatic account controls in place (that prohibit accounts below a certain karma threshold from creating posts or commenting too frequently).