Maybe have a friend buy it for you from the States and send it over?
Maybe make the buy over the phone (which I'm sure is possible, but prolly less safe actually)?
But 600 CAD? I got it... £175, which is 350$ 3 years back... Now in
Untitled Document it is at £148 = 300$ 299 CAD (yay! CAD is higher than the US $)
audioMIDI.com - Sennheiser USA - HD600 Headphones : $365 this IS almost half price from the 600 CAD that you mention. And I'm pretty sure that they take phone orders, as well as Internet buying IS safe. I've bought from them (audiomidi, and I'm in London) if it's of any use really.
But honestly with those headphones you can outdo any cheap monitor quite easily, regarding levels. The only problem is that the stereo seperation is a bit off (because they are headphones, not for any other reason), but regarding mixing it should be perfect.
Just so you be aware (I think you've heard my music, so you know what I write):
I
still use the soundcard which was onboard my machine: A Realtek AC97 or something simmilar. Yes, I have a Lynx which is excellent, but not connected cause I don't have means to listen to it (no monitors, no mixing desk, no preamp for the headphones, etc).
I
still don't have monitors. I have some 50$ mini hi-fi system, which gives great results, according to how I listen music and my headphones.
I have
never recorded anything live, or myself, or any mic (I don't have any mics)
but
I have spent a lot of money in software and samples. A LOT!
What I mean is: Depending on what you do (if you are 100% digital for example), you don't need... a soundcard really. Yes it plays a role, but not the most impotant.
If you have excellent headphones, you don't need monitors, unless ready to spend A LOT OF money (as I said, by listening for months now, I'm sattisfied with high end monitors, The lower and cheaper ones, simply sound worst than my headphones).
If you have a good set of monitors, then don't need the headphones, etc...