Amazon offers its Prime members the Plantronics M50 Bluetooth Headset, model no. 85550-63, for $19.99 with free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise, shipping costs $5.32.) That's tied with our mention from last November and the lowest total price we could find by $7. It features up to 11 hours of talk time or 16 days of standby time.