Every one of my sales Mercari has double and in some cases triple charged me for shipping after the sale was complete. I made $6.46 on a $48 sale because they quadruple charged me for a shirt saying a t-shirt in an envelope weighed more than 3 pounds when it weighed 9 ounces at the post office. This app is a scam you will just be giving your items away. You'd be better off donating them to the needy.