I was in the market for a new pack, and had way too much freetime and searched all the sites I check to find the cheapest deals. This was comiled a few days ago, but the prices are likely the same. This is mostly for the older packs since the new ones are the same price everywhere.

Infinity $109 domsoutdoor.com
Intuition $99 domsoutdoor.com
Vision $66 prolitegear.com
Continuum $89 domsoutdoor.com
Delirium $110 prolitegear.com
Gust $59 domsoutdoor.com
Jam $81 backcountry.com
Team $108 backcountry.com
Lift-less $63 backcountrygear.com
Speed $79 domsoutdoor.com
Powder-8 $59 domsoutdoor.com
24 $49 domsoutdoor.com

I searched these sites:
golite.com
prolightgear.com
domsoutdoor.com
backcountrygear.com
ccoutdoorstore.com
campmor.com
backcountry.com
progearzone.com
northernmountain.com
rei.com
rei-outlet.com
ems.com
mgear.com
sierratradingpost.com
mountainhideout.com
mtntools.com
gearexpress.com
mec.ca
campsaver.com