EA Electronics via Amazon offers Prime members the Acoustic Research Bluetooth Indoor/Outdoor Portable Speaker in White/Gray, model no. AWSBTSK, for $18.64 with free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise, shipping adds $7.95.) That's tied with our January mention as the lowest total price we've seen. (Outside of other Amazon sellers, it's a current low by $7.) It can be customized with speaker skin from Skinit.com and features a 32.8-foot range, auxiliary input, weather-resistant construction, and hidden compartment for a phone or MP3 player. It uses six AA batteries, not included, or the included AC adapter.