For what it's worth, I've noticed the DL fares from PDX-YYJ running just under $100 one-way in coach and around $165 in first class...QX is usually at least $150 (for coach, no first class of course).
The train is always a good option although the times don't always work out the best....you leave Vancouver at the crack of dawn (6am) and coming back it gets to Vancouver around 11pm.