Boom Box via Amazon offers the Mighty Rock Touch Wireless Bluetooth Portable Speaker in Black, model no. 5110, for $25.99. Coupon code "7FO2S6TU" cuts that to $19.99. Plus, Prime members bag free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise, shipping costs $6.55.) That's $40 off list and the lowest total price we could find. It features dual drivers, a passive subwoofer, Bluetooth 4.0, a microphone, and up to a 6-hour battery life.