I use www.travelocity.ca all the time - it has saved me a ton of money. It gives Canadian prices (which I love) and is fairly easy to use. I just put my info in there and then call up any travel agent and give them the flight numbers and price that I got from the net and they honour it. If you need any help with this let me know and I can help you find a cheap flight
That is a good point - I'm starting to source my flights for September and so far the cheapest flight by far is from Buffalo - 185.00 Canadian which is about 120 bucks american.