I buy lots of bike stuff from the US. Get it shipped USPS - US Postal Service (not FEDEX or UPS) and you'll only pay GST + $5 handling fee. I have ordered Ortlieb products several time from Wayne at
www.thetouringstore.com and never paid any other duties. I am all over supporting Canadian businesses first if possible, but for the specialty gear I want that is often not possible or far too expensive.
As far as I am concerned Wayne, Peter White, Harris Cyclery, Wall Bike and such are part of my virtual community and I will happily support them.