Orders shipped outside the United States are subject to duties and taxes imposed by the destination country/post office.
For orders to Canada, specifically, Canada Post (via DHL, or directly) assesses fees on orders for both taxes as well as a handling fee for collecting the taxes (usually only on larger orders). We disclose all information that we know about on our website. At checkout (when you have at least 1 item in the cart), we explain that all Canadian orders are shipped from Irwindale, California, USA with 4-10 business days approximate delivery to Canada. Additional information is provided that explains that orders shipped to Canada are subject to local taxes and a $7 handling fee (usually on larger orders). The funds are sometimes collected by DHL, but this is on behalf of Canada Post (Royal Mail).
Had you placed your order with a Canadian reseller (who ships from Canada), you would have to pay the taxes upfront. But since we ship from California, we do not collect the taxes, however they are sometimes collected at delivery as explained above. Overall, most customers find that it is cheaper to buy from us than Canadian resellers because our prices are often lower, our shipping costs are often lower (we even offer free shipping at times with promotions), our shipping times are reasonable, and we do not collect taxes upfront.