You should shop around by: check www.hotels.ca(or www.expedia.ca), www.travelocity.ca, www.hotwire.ca and their own hotel website.
Then call the hotel directly, ask for the rate. If the hotel's rate is higher than what you've searched, then tell them you found rates from xxx to see if they match the rate...
I think Expedia is more expensive than the other site...
I booked my cancun vacation few years ago through travelocity and it's slightly cheaper than Expedia for the same All Inclusive Deal...
i used expedia in the past...i've also booked directly on the hotel's website.. but now that i learned about hotwire, i think i'll be using it next time if i don't mind a surprise.