You may want to add shipping / packing costs to physical goods. In this system you have the option for each physical product to have no shipping, fixed shipping for all destinations or variable shipping depending on destination.
For fixed shipping costs, which will be the same for all destinations, choose that option in the Product definition page and enter a value for that product.
For variable shipping costs, you first need to set up your shipping destinations. You then enter the reuqired costs for each destination when you create or edit the physical product.
When shipping has been added, and the customer purchases that item, a page will appear to allow them to select their destination and hence select the shipping costs.