REI offers the Kelty TraiLogic PK 50 Backpack
in Grey/Citron for $99.93
with free shipping
has it in size S/M for the same price.) That's the lowest total price we could find by $40. Features include a 50-liter capacity, ventilating back panel, easy-access top and wing pockets, detachable front pocket, water bottle pockets, chest strap, hipbelt with pockets, and integrated pull-out raincover. It's available in sizes S/M and M/L.