Weigh the packed box, then write the shipping

The listing is done, the price feels fair, and then shipping is a round number you liked. At the counter the box is heavier, longer, or needs a second sleeve. The difference comes out of the hours you already underpriced.

Pack one the way you will actually pack it. Weigh it. Measure it. Put that cost in the listing, or fold a real average into the item price and say shipping is included. Do not invent a cheap number to soften checkout.

Buyers on Doshe will pay for a box that arrives whole. They will not thank you for a surprise bill, and you will not thank yourself for eating the tape, the cardboard, and the extra mile.