Adorama offers the Westone Um Pro20 Dual-Driver Universal In-Earphones in Clear (pictured), model no. 78515, for $189 with free shipping. That's the lowest total price we could find by $71. (Most retailers charge $299 or more.) They feature a frequency response of 20Hz to 18kHz.

Also available is the Westone Um Pro30 Triple-Driver Universal In-Earphones in Smoke, model no. 78489, or Clear, model no. 78516, for $279.99 with free shipping. That's another price low, this time by $63. (Most retailers charge $400 or more.) They also feature a frequency response of 20Hz to 18kHz.