REI Garage offers the Gregory Miwok 6 Pack in Green for $33.73 Choose in-store pickup to avoid the $5.99 shipping fee. That's the lowest price we could find by $35. It features a hydration sleeve and zippered main compartment with two internal mesh organizer pockets.

Note: REI members can take an extra 20% off via coupon code "GEARUP20". A lifetime membership costs $20. (You can sign up at checkout.)