Secondipity offers the refurbished Sony Bluetooth Wireless On-Ear Headphones in Black, model no. MDR-ZX330BT/B, for $39.99 with free shipping. That's $36 below the best price we could find for a new pair. They feature 1-touch listening via NFC, 20Hz to 20kHz frequency response, 30mm drivers, built-in microphone, and up to 30 hours of playback.
Note: No warranty information is provided.