BuyDig offers the Audio-Technica ATH-AD900X Audiophile Open-Air Headphones for $139. Coupon code "EMATPRO" cuts them to $129. With free shipping, that's the lowest total price we could find by $26 and the best price we've seen in over a year. (For further comparison, we saw a refurb pair for $99 shipped last week.) They feature a detachable 6.3 mm adapter, 53mm drivers, and 5Hz to 40kHz frequency response.

Also available are the Audio-Technica ATH-A900X Audiophile Closed-Back Headphones for $139 before the above coupon, $129 after. With free shipping, that's the lowest total price we could find by $31. They feature 53mm drivers, frequency response of 5hz to 40kHz, and detachable 6.3 mm adapter.