Just came across these cheap backpacks. I have purchased from this seller and can recommend them!
Features:Backpacks
Colour: MixMade from 100% Polyester
Classic school backpack
Exterior organiser pockets
Large main zip compartment
Ergonomic padded back panel
Adjustable padded shoulder straps
Size + Fit Guide:Dimensions: 44 x 28 x 19cmVolume: 20L
Also available:
New-Burton-Prospect-Backpack-21L-Mesh-Luggage-Travel-Black Sold out
New Volcom - Basis Poly Backpack 20L Sold out
New Uppercut Deluxe - Filled Toilet Bag $16 (Was $80)
Sandqvist - Charlie Satchel Cotton Canvas Leather $41.80 (was $209)
They also have 80% off some surf cloths.
This does not look like an $80 backpack but $16 shipped is a good price.