BuyDig offers the Seagate 3TB Expansion USB 3.0 External Hard Drive, model no. STBV3000100, for $100. Apply coupon code "VISAVDAY15" and pay with Visa Checkout to cut the price to $84.99. With free shipping, that's the lowest total price we could find by $14, although we saw it for $10 less last fall. Deal ends January 29.