Jet.com offers the LG Electronics Music Flow P7 Portable Bluetooth Speaker, model no. NP7550, for $45 with free shipping. (Adorama charges the same.) That's the lowest total price we could find by $40, although it was $2 less a month ago. This 20-watt speaker connects with up to three devices at once and features a rechargeable Li-ion battery, up to 9 hours of playback time per charge, and SoundSync technology (to receive TV audio in another room).
Note: You can also receive additional discounts during checkout by waiving free returns or by choosing select payment options.