Reply To: What if I don't want to buy back the chometz from the goy?

There absolutely is a buying back. I’ve seen it myself. The goy comes after Pesach and the rov reminds him that payment is due, and asks whether he’s found a buyer, or otherwise come up with the money. The goy says he has not, so the rov offers to buy it himself on behalf of the original owners, for a price slightly higher than the sale price, so he will make a profit. They make several different kinyonim just as they did on Erev Pesach (kesef, sudar, tekias kaf, signatures, drinking).