Alas Dear Shoppers...despite our desire to believe in Fairy Tales, there is no such thing as "free shipping" nor the perfect Prince Charming for that matter. :-)
I have made an honest effort to be equitable, and pass along true value and savings to my customers on combined purchases.
My customers across the globe can easily estimate their postage charges by navigating to the "Shipping & Payments" tab, and entering their quantities desired. These discounted charges are automatically reflected when you proceed through check-out as well. Usually, there is no need to request an invoice on combined purchases.
Please be kind, and cognizant of these efforts, when rating my shipping services in feedback, so that I may continue to keep my overall pricing low for those many savvy customers, who enjoy these shipping discounts on multiple items.
As for Prince Charming...well, you are on your own there ladies. ;-)