Finding a buyer for your used Apple Watch is hard but negotiating for a fair price is even harder. Most buyers give meager offers for used Apple devices, especially Macs, iPhones, and the old Apple Watch series.
It's no fun haggling prices day and night with a potential buyer, and there's no reason even to do it in the first place, especially when you have a better option. You can sell your Apple Watch online with SellShark and get the best prices every time.