Threadjacking.
If you are interested in extreme quality at a good price
This is the pack I use. Osprey Quasar. It's a climbing pack, but I couldn't have asked for a studier pack. I paid $90 for mine. It's super strong, carried about 80lbs in it personally, and it has a bunch of adjustable straps for load displacement. I use it for school, riding, everything. It has a spot for a water bladder in it too.
/Threadjacking.