Oof.. looks like you just missed the end of a lot of internet specials by a week and a half, but I think those rates were only good until early December - you're going smack dab in the high season.
Anyway, you might still be able to swing a good deal on Air New Zealand. Try their Canadian web specials page
Also, Qantas has had some killer deals lately... Check out their "Plan Ahead Fares"
page, but keep in mind these are prices from Los Angeles.
Generally, flying into Sydney is the cheapest, since it's the biggest hub in the country. Occasionally, you'll find prices to Brisbane to be lower, but that usually won't be a nonstop flight.
You can also look at various Asian airlines for flights into Australia - the price might be a touch higher, though, but you can get free stopovers in places like Hong Kong, Singapore, etc. - not bad if you're going on a big-ass trip!