I don't understand what you mean by selling his debt.
I can understand how he could buy it at a discount, which would equate to a partial discount. But selling it? Selling what?

Lots of people are selling their pirate accounts at a discount. He probably has some fake accounts, and he could be selling them. That would also explain why he's still hanging around. If he didn't it would be pretty much impossible to sell them even at a discount.