You also have to take into account the materials for packaging as well as the time to actually ship the product when talking about shipping charges. When I sell on Ebay, (which is not very often) I charge enough so that I can go out and buy a box, good packaging material, and cover my time and gas to drive to the post office, as well as the base charge of just shipping. Just remember that it is not only the actual shipping charge you are paying for, but the total cost of shipping an item, which is higher than most people realize.