You can get Jansport Diablo on closeout, I'd be cheaper than a Camelback discount and quality is just as good plus it has a better bladder system. It has a first generation Nalgene bladder which isn't quite as good as the current 3rd generation CXC (no magnet bite valve mount, different tube routing, slightly smaller opening) but its only $25 for the bag and the bladder (or $40 if you don't want the light blue color they are selling at WS in the link below instead -
moabsports).
http://wheelandsprocket.com/itemdetails.cfm?id=10786
I have the same pack and have been using it for about 6 years now - its my favorite and I've tried tons of them. Pack is still working great (other than a blood stain on the straps from a mtb accident) and I actually have another unused spare I bought on clearance a few years ago for $40 since I like it so much. It fits a multitool, a few hangers, a shock pump, a tire pump, 2-person first aid kit, rain breaker, food, camera, keys, wallet, cellphone, 100 oz quick disconnect bladder, and spare tube. Its wide on the bottom and distributes the weight over your waist rather than up high like most other brands (like Camelback)
These are some of the various models I've had - 2004 Jansport Diablo is top center in Blue (not pictured but also Dakine, Northface, Ultimate Directions, K2, Platypus, Gregory, and maybe one or two others over past few decades):