Targus Motor Laptop Backpack (Black) for $9.99.  Order online for in-store pickup at Best Buy to lock in the price, ensure availability, and save on shipping.  Otherwise, shipping is $5.50 for a total of $15.49 shipped.  Here is a screenshot for your reference.  It fits most laptops with up to a 16" display, and features multiple accessory compartments, adjustable shoulder straps, durable polyester cordura material, side water bottle pockets, and padded back panel.