Posts: Insubstantial posting
If this is the case then it would be a very high risk to purchase this account. The risk of a perm ban is high and if this happens then all of your accounts will be banned as well.
@Quickseller I see you're very experienced here, what exactly constitutes an "Insubstantial posting" can you give me an example?
According to the OP the kind of posts that were made by the account you are selling
An insubstantial post will generally be one that is very short, typically only one or two lines, it will add no content to the conversation and will almost never receive an kind of a response from anyone further down the thread.