Newegg offers the Sennheiser HD 239 On-Ear Headphones for $59.95. Coupon code "618CMPTS78" cuts it to $39.95. With free shipping, that's $30 under the lowest total price we could find, although we saw them bundled with a bluetooth speaker for a few pennies cheaper last winter. These open-back headphones feature a frequency response range of 16 to 23kHz, a foldable design, and a storage pouch.