Western Digital offers its factory-refurbished Western Digital My Cloud Mirror 4TB Personal Cloud Storage Gigabit Ethernet NAS, model no. WDBZVM0040JWT-NESN, for $299.99 with free shipping. That's $49 under the lowest total price we could find for a new unit. It features two USB 3.0 ports, iTunes compatibility, and dual-drive storage with an optional mirror mode. A 6-month Western Digital warranty applies.