Walmart offers the Ematic Rugged Life Bluetooth Speaker in several colors for $10.73. Opt for in-store pickup to dodge the $5.99 shipping charge. (Home Depot has it for the same with free in-store pickup. That's the lowest price we could find by $10. It features a 30-foot range, answers calls, and is water-resistant.

Update: Home Depot now offers it for $9.99 with in-store pickup. Walmart is pennies more.