VMInnovations via eBay offers the open-box Sennheiser Momentum In-Ear Headphones for iOS in Black/Red, model no. 506231, for $54.99 with free shipping. That's $14 under the lowest total price we could find for a factory-sealed item. They feature a frequency response of 15Hz to 22KHz, 18-ohm impedance, three button in-line remote.
Note: These headphones are new but may be missing the original packing.