BigDeals via eBay offers the Philips Flexible Hook Earphones in Black, model no. SHS3200, for $5.99 with free shipping. That's the lowest total price we could find by $5. They feature a 20Hz to 20kHz frequency response, 15mm driver, and a 3.9-foot cable.
Note: This item is new, but will arrive in bulk packaging.
A close price: Blinq via Amazon offers them in Pink for $6.59 with free shipping.