Botach Tactical via eBay offers the Lewis N' Clark Sport Backpack
in Black or Blue, model no. 9110, for $17.99 with free shipping. That's $4 under our mention from last month and the lowest total price we could find by $2. It features 1,680-denier and and 420-denier polyester construction, water-resistant coating, air mesh back panel, and more.
Update: A reader noted that Altatac via eBay offers the same backpack for $17.95 with free shipping.