Due to free shipping w/ purchase (limited offer), this is the cheapest price I have seen. Enjoy!
HGST Deskstar NAS H3IKNAS600012872SN (0S03839) 6TB 7200 RPM 128MB Cache SATA 6.0Gb/s 3.5" High-Performance Hard Drive Retail Kit
• 7200 RPM, 6Gb/s SATA Interface, 6TB
• Outstanding Reliability: 1 million hours MTBF, Rotational Vibration Sensor, 24/7 availability
• No additional hardware required
4TB for $214 as well