Ebay offers All in Motion 15" Travel Laptop Backpack for $16 (reg $40) with free shipping.

Product Description:
Water-resistant, on-trend backpack is designed with various exterior and interior zip pockets — including two bottle holders and a front-zip pocket — to help separate and organize your items. The main zippered compartment is perfect for larger belongings, and the laptop pocket is ideal for bringing your electronics on the go. You can find the right fit for comfortable carrying with the help of adjustable straps and a loop handle.
All in Motion: Made for every move, priced for every day.

• Dimensions (Overall): 17.5 Inches (H) x 12 Inches (W) x 7 Inches (D)
• Weight: 1.38 Pounds
• Suggested Age: 13 Years and Up
• Shell Material: 100% Recycled Polyester
• Bag Structure: Softside
• Interior Features: Laptop Pocket
• Exterior Features: Front Zip Pocket, Backpack Straps, 2-Bottle Holders
• Main Compartment Closure: Zip Closure
• Handle Type: Carrying Handle
• Capacity (Volume): 21 Liter
• Protective Qualities: Water-Resistant
• Used For: School
• Fits Laptop: Up to 15 Inches
• Battery: No Battery Used
• Care & Cleaning: Spot or Wipe Clean