Groupon offers the Able Planet Noise-Canceling Headphones in Black or Silver, model no. NC300B, for $29.99 with free shipping. That's tied with our April mention as the lowest total price we've seen. (It's a current price low by $69.) These headphones feature an adjustable headband, in-line volume control, LINX audio technology, and 20Hz to 20kHz frequency response.