Amazon offers the Toshiba 5TB Serial ATA 6Gb/s Internal 3.5" Hard Drive, model no. PH3500U-1I72, for $159.99 with free shipping. That's the lowest total price we could find by $15. It runs at 7,200 rpm and features a 128MB cache.
Note that this item is currently out of stock, however it can still be ordered for delivery when available.