As one of its daily deals, Amazon offers the Seagate 4TB Serial ATA 6Gb/s Internal Hard Drive, model no. ST4000VN000, for $136.99. With free shipping, that's the lowest total price we could find by $23, although we saw it for $16 less last winter (which required padding). It features a 64MB cache, NAS error recovery control, improved vibration tolerance, and advanced power management. Deal ends today.