Here's a great offering from Amazon.com: the Buffy The Vampire Slayer - Collector's Set (40 Discs) for $99.99 US. This has been marginally cheaper before at Amazon.com ($95), but that was a one day special only, and it hasn't been that cheap since. For comparison, this set still sells for above $200 in Canada. Futureshop is featuring it for $284.99 for instance.

http://www.amazon.com/Buffy-Vampire-.../dp/B000AQ68RI

Remember, Amazon.com does ship DVDs, Books, and Music to Canada without hassles. There is a standard shipping fee, but items usually ship ship from a Canadian warehouse, so brokerage and duties shouldn't be a concern.