Allow purchases of multiple items without having to create a unique shipping price for each#67

I sell unique items. When international customers make a purchase of 2 or more items it will not charge a shipping fee for each item if they have they same shipping category. So they pay the same shipping fee whether they buy 1 item or 100 items if those items are all in the same shipping fee category. When I called about this I was told I need to create a unique shipping category for each item. This would be impossible as all I have are unique items. The only other option I have is to use an app which is costly and difficult to set up.

xxxz