Holy crap shipping is expensive. Im out if it stays at that price. $30 U.S. shipping, thats the price of one of these sets. You should work on finding some proxies to try and cut the shipping in half because I think for an add on set that is only $30, youre going to lose a LOT of people that don't want to pay the same or more in shipping cost.
edit: wait i just read through it and the example prices you used are for a 4.4lb package? If thats correct and its based on weight it probably wont be so bad as these shouldnt even weigh 1lb. But ill wait to get this confirmed.
But the price of each kit is quiet cheap I think.
This time I have't use a USA local vendor to sell them, so I lower the price of each kit.
But, I have to let SP send the product to China vendor KP first and then send out , the shipping are higher than we thought.
As, you know , we also ask taobao buyers for 58yuan extra international transportation·fee, that is about 10USD,
I think KP has charged this on those GH buyers in the Shipping fee.