Just a quick deal post.
Variety of Herschel backpacks and MacBook sleeves quite cheap at Surfstitch. Not my cup of tea personally, but they seem to be popular.
Heritage Backpack shown on link
Heritage Offset $39.19
Herschel Classic $31
Heritage MacBook sleeve $23
Cotton daypack $22
More available via the sale tab.
See here for all Herschel sale.
Also saw some (yellow) Vans that are available in all sizes - $28 (was $100): available here or white for $35.
Why are these super lame looking backpacks now in style? Looks like something a 4 yr old might take to school lol