As one of its daily deals, Groupon offers the Sharper Image Ultrasonic Cool Mist Humidifier, model no. EV-HD15, for $64 with free shipping. That's the lowest total price we could find by $47. Sales tax is added where applicable. It features a dual 1.6-gallon tank (with up to 32 hours of run time per tank), LED indicator (for water level), and automatic shutoff. Deal ends February 12 at 12:59 am ET.