Amazon.com offers the Sennheiser MX55 Twist-To-Fit In-Ear Stereo Headphones for $12.99. Shipping adds about $6, or pad your order over $25 for free shipping. Even with shipping, it's within a buck of the lowest total price we've seen. These headphones feature a frequency response of 17Hz to 21kHz.

Trade in your old headphones along with this $5 mail-in rebate to cut it to $7.99. Rebate ends September 30.