Amazing Wireless via eBay offers the Unlocked ZTE Axon M Z999 64GB Dual Screen GSM Android Phone in Carbon Black for $249.99 with free shipping. That's the best price we could find by $79. Features include:

5.2" 1920x1080 (1080p) display

Qualcomm Snapdragon 2.15GHz + 1.6GHz dual-core processors

20MP rear camera

4GB RAM, 64GB internal storage

Android 7.1 (Nougat)