If your username means you are BC, then stay away from places like Performance, Nashbar, Glory Cycles and the like.
These places tend to ship with either UPS or Fedex and both of those services will end up costing you a bunch of extra money - they charge you a "brokerage" fee to bring the goods into the country. This is not duty, or taxes or anything else as bike parts are duty free. It is a completely bogus addition to their bottom line.
I have used Biketiresdirect a number of times and my recollection is that they mailed the product - so no extra charges. Same with World Class Cycles.
Also be aware of the tendency of certain of the outlets to charge wildly excessive "shipping" charges to even mail to Canada. Universal Cycles was mentioned. I have used them when in the US on vacation, the shipping charge was $8. The estimated shipping charge - by Universal - to mail the same goods to Canada was $60.
The best outlets, with best prices, and fastest shipping are the UK sites such as PBK, Wiggle, Total Cycling and Ribble.
I have used all of these and have been very happy with the service from all of them.
If you are going to order online from US outlets - only order from those that USPS - otherwise you are going to get a very nasty surprise in the final billing.