AblePlanet Musician's Choice Headphones for $20 + free shipping
BuyDig via eBay offers the Able Planet Musician's Choice Noise Canceling Headphones in Black, model no. NC180B, for $19.99 with free shipping. That's the lowest total price we could find by $9. They feature a 20Hz to 20kHz frequency response, folding design, and detachable cord.