Creative via Amazon offers the Creative Sound Blaster E3 Portable Bluetooth USB DAC / Headphone Amplifier, model no. 70SB161000000, for $79.99 with free shipping. That's the lowest total price we could find by $40. It features support for headphones up to 600-ohm impedance, up to 17 hours of playback, dual headphone outputs, microphone input, line in, and USB.