As one of its daily deals, Buy.com offers the Seagate 4TB Backup Plus USB 3.0 External Hard Drive, model no. STCA4000100, for $189.99. Coupon code "50AC4FC" cuts it to $174.99. With free shipping, that's $0.04/GB, $5 under our mention from five days ago, and the lowest total price we could find by $15. It's compatible with Windows and Mac and features two backup scheduling options, social network sharing, and more. Deal ends today.