Amazon offers the PYLE Waterproof Bluetooth Speaker, model no. PWPBT60, for $40.99 with free shipping. That's the lowest total price we could find by $4. It features a 60Hz to 20KHz frequency response, 33-foot range, and 1,400mAh battery with USB charging. Deal ends December 23.
Orders placed by December 19 are guaranteed to arrive by Christmas.