Timberland Holderness 15.4" Laptop Messenger Bag for $19.99 shipped.  Here is a screenshot for your reference.  It features a padded compartment for fitting a laptop with up to 15.4" screen sizes, multi-compartments for organization, 2 water bottle/utility pockets, media port entry, and adjustable ergonomic shoulder strap.  Most places have this messenger bag for about $34.