Well this is not to be augmentative, but for the record;
I have ordered a few items over the years from Tartanweb, including a jacket and waistcoat.
There is over a $150 difference in the prices of the jackets in question, $270 vs. $425.
As I recall, the shipping on my TW jacket order a few years ago was less than $20, and it was sent via royal mail - parcelforce so there was no duty fee.