Hanes via eBay offers the Champion Men's Authentic Cotton 9" Shorts with Pockets in four colors (Black pictured) for $8.99 with free shipping. (Amazon has them for the same price with free shipping for Prime members.) Excluding the mention below, that's the lowest total price we could find by $3. They're available in sizes S to XXL.
A close price: Sears has them for $9.49 with free in-store pickup.