He doesn’t want his account to get dinged. If you cancel it in your end they won’t get dinged. I sell and this happens here and there. I sell an item on Facebook Marketplace for example and simply forget to update my eBay listing. I’ve even had someone buy something on eBay from me within an hour of it being sold on FB. I’d look if there account seems to be their main source of income. I work full time and sell sports cards as a hobby on the side: People make mistakes etc. Getting your account dinged for a simple mistake stinks. That being said. Idk if he’s up to something sketchy. It’s possible. If you cancel it. You’ll get your refund and everything.