You can find an up-to-date list of production and shipping costs for all the products we offer at the link below:
Additional shipping cost? What does that mean?
Additional cost is the extra shipping cost for shipping another item of the same type within that order.
For example shipping for one mug is $5.00, so shipping for two mugs would be $8.50 as the additional cost is $3.50. And for three mugs $12.00 etc.