We honestly did not anticipate SUCH an overwhelming response from outside of the US and are humbled by your interest globally! We were originally opting to handle shipping on a case by case basis, however this ended up being more confusing! We've analyzed it and noted that the cost to ship each physical deliverable averages between $10 and $15.
You may choose to either add $15 to your pledge at the time of pledging (so, if you get the $50 reward, please add $15 to make it $65), or you can simply pledge the $50 and at the time of shipment, we will communicate with you to find the most cost effective method to get this to you (and will handle shipping outside of Kickstarter).
Sorry for the confusion, and unfortunately it is too late to add shipping costs to the rewards to streamline the process. Please contact us if you have any questions about this. We will gladly work with you.