Newegg offers the Seagate 4TB Barracuda Serial ATA 6Gb/s Internal Hard Drive, model no. ST4000DM000, for $139.99 with free shipping. (Amazon charges the same for Prime members.) That's the lowest total price we could find by $9, although we saw it for $10 less in May. It runs at 5900 rpm and features a 64MB cache.