TomTop offers the M2 0.42" OLED Touch Screen Smart Wristband in several colors (Black pictured) for $11.99 with free shipping. That's $14 off list and the lowest price we could find. It features a heart rate and sleep monitor, pedometer, Bluetooth 4, and is compatible for Android 5.0 and iOS 8.0.

Note: This item ships from China and may take 4-6 weeks to arrive.