Bestbuy offers WD - Easystore 5TB External USB 3.0 Portable Hard Drive - Black for $119.99 (orig. $134.99) with free shipping.

Product Description:
Carry and preserve important files wherever you go with this Western Digital easystore portable hard drive. The 5TB capacity offers ample storage space for your files, while the USB interface ensures compatibility with a wide range of devices. This Western Digital easystore external hard drive has a compact profile for increased portability, and the included WD Discovery software makes backing up data easy. 

• USB 3.0 interface
  Offers an easy-to-use connection to devices. Backward compatible with USB 2.0 for simple connection to your computer. USB-powered.
• Compatible with Mac and PC
  For flexible installation options.
• 5TB storage capacity
  Provides ample space for storing documents, photos, music and more.
• Portable design
  Lets you take your data on the go.
• Automatic backup options
  Allow you to use compatible software to back up your files to the server. Equipped with WD Backup software. Simply download WD Backup software, plug in your drive and set your hourly, daily or monthly schedule.
• WD Drive Utilities™
  Allows you to configure, manage and diagnose your drive.