Ebay offers Adidas Men's Adicolor Classic Backpack for $11 (reg $35) with free shipping.

Product Description:
This adidas backpack lets you take your day in stride, whether you're headed to class or exploring the city. The spacious main compartment has room for your laptop, gym clothes or anything else you need for the day. An extra front pocket and side pockets keep smaller items within easy reach. Comfortable straps let you carry it all with ease.