I took a long summer vacation years ago, visiting AZ, UT, WY, MT, AB/BC - stayed at nearly all the big parks.

Banff-ll-jasper lodging (and dining) costs were ridiculously expensive.

Low cost of my month long trip - Best Western in West Yellowstone, MT ~43 USD a night. I stayed there extra days due to the favorable rates.

High cost - Something that looked just like a Best Western in Lake Louise, but actually a little dirtier and more worn out, $210 USD a night. Ditto Jasper, it was maybe ten bucks less. I felt like I was being extorted the whole time I was there. Fortunately I was distracted the whole time by endless mathematical conversions from gallons to liters, miles to kilometers, dollars to other dollars, lakes to lacs (you could save a ton of money right there on signage).

This trip was planned and reserved more than 6 months in advance, and I got the best rates available at the time. It appears to me that there's no way to vacation in the canadian rockies on the cheap, except maybe sharing biker/hiker camping sites. A shame too, since it's the most gorgeous scenery of the entire rocky mtns. But maybe thats the goal - get the money, then move the tourists on out. Visiting the area gave me a whole new appreciation for Wal-mart and Wendys.