This dates back to 2008, but might help?
"As for the Canadian shopping experience
you must shop in US$, which isnt such a big deal these days, but they calculate the duty and tax for you at checkout. Unfortunately, ordering shoes from anywhere out-of-country is expensive since 90% of the time they are made in an Asian country. This means that they are charged a duty of anywhere between 18%-22%. I think Zappos just estimates 20% across the board - so you are looking at 20% + 14% tax (in Ontario) + $10 shipping. The $10 shipping doesnt sound so enticing now, does it? I think it is worth it if it is something you cant find at home and is perhaps much less expensive in the US, which happens. Even though the total price is a bit shocking, it is better to know before you purchase. And unfortunately there isnt really anything Zappos.com can do about duties and taxes."