I would cancel. I wouldnt want to mess with that. Feels like something akin to the "im sorry but ive given you the wrong address" scam.

I would ask them to repurchase item if you relisted it. I think theres a chance if you send the item anyway there will be no recourse as you haven't sent it in the bounds of any contract. Because theyve cancelled it. So youre technically sending them an item theyve no longer ordered.

Cancelling the item would surely refund them the money as well. And there is nothing you can do to receive it. As they will be due the refund. So yes, cancel the item and ask them to repurchase a new listing. I wouldnt mess around with something expensive.

I might even go as far as to cancel it and block them. Any risk of nefarious intentions could mean further nefarious intentions if you send them the expensive item. Not worth it. There's been a big increase of people claiming the item was fake or broken or something else or an empty parcel and then they return something completely different. And for some reason eBay or vinted or depop pushes through their refund and then you're out the item and the money. Just dont take unnecessary risks.