Shipping charges from Luxire are $15.
The duties, taxes and fees are then your responsibility and you will be charged by the carrier (e.g. FedEx).
From my experience of roughly 15 shirts, 2 shorts and one pair of pants is that you will only be charged by FedEx if you order more than $200 or so. My guess is that FedEx can only assess fees to so many packages in a day and they will make it worth their while instead of worrying about packages with insignificant value. Probably some luck involved as well depending on how busy it is and who is working that day.
Budget ~15-20% for the taxes, duties and fees from FedEx.