Which listing?
When a listing it set up with calculated shipping, it automatically shows the exact calculated postage cost between your ZIP Code and that of any member who looks at your listing. Potential buyers do not have to do anything; it's automatic.
When a listing should show a cost but instead says "unspecified," usually there's an error in the weight or dimensions, such as setting up First Class package weigh a weight over 1 pound. So check those.
