Newegg offers the Seagate Backup Plus 4TB USB 3.0 External Hard Drive, model no. STDR4000100, for $169.99. Coupon code "0915TXTBK48" cuts it to $159.99. With free shipping, that's tied with last month's mention and the lowest total price we could find by $10. This 2.5" drive comes with an offer for 200GB of OneDrive cloud storage and is powered via USB. Deal ends September 17.