VMInnovations offers the Sennheiser Clip-On In-Ear Headphones, model no. OMX60, for $29.95. Coupon code "JMYHGMX" cuts it to $17.99. With free shipping, that's the lowest total price we could find by $7. They feature a frequency response of 18Hz to 21kHz, in-line volume control, and an ear adapter set.