TomTop offers the Cheng Xintu 55-Liter Water-Resistant Hiking Backpack in several colors (Royal pictured) for $21.99 with free shipping. That's the lowest price we could find now by $3, although we saw it for $2 less in March. It features a large main compartment with numerous smaller pouches, detachable internal aluminum frame, padded shoulder straps and back support, and adjustable chest and waist belts.