A word about shipping prices: I stopped using the ebay postage calculator because it is just too weird. I end up having to manually discount/rebate excess charges. I have chosen to use flat rates instead. The price shown depends largely on total package weight. 1st Class postage is tiered. 2 - <5 oz, 5 - <9 oz, 9 - <13 oz and 13 - <16 oz. After that we get forced into Priority Mail. If the expected final price is fairly high I have to add in the expected cost of insurance. Unless stated otherwise, I usually insure 1st Class packages. In this case I am waiving the insurance to get the shipping cost down.
The price includes also includes the cost of the box or padded envelope. If I get lucky I'll have a box in the house I can reuse, but usually not. In the end I usually break even on shipping costs. I try to keep them as low as possible without losing money.