VM Innovations offers the refurbished Sennheiser PMX 685i adidas Sports In-Ear Headphones for $31.99. Coupon code "8856T" cuts it to $27.99. With free shipping, that's $2 under the lowest total price we could find for a new pair, although we saw a new set for $8 less this past winter. They feature a frequency response of 18Hz to 20kHz, microphone, and in-line controls.
A 90-day VM Innovations warranty applies.