BuyDig via eBay offers the Audio-Technica QuietPoint Active Noise-Cancelling In-Ear Headphones, model no. ATH-ANC23, $29 with free shipping. That's the lowest total price we could find by $11. They feature up to 90% background noise reduction, 12.5mm drivers, 20Hz to 20kHz frequency response, and 105dB sensitivity.