Postage and package

Hi, I'm hoping someone can help me clarify this for me. 

 

Whenever I list an item for sale, I make sure to include a charge for postage and packaging so that the buyer covers these costs. However, once the item sells, it seems that I am still being charged for postage by ebay.

 

When I go back and view the listing after it has sold, it shows the postage and packaging as "free," which is confusing and frustrating, as this means I am effectively losing money on the sale.

 

I'm not sure if this is a glitch or if I'm doing something wrong when creating the listing. Has anyone else experienced this or knows how to fix it?