Staples offers the Maxtor OneTouch 4 320GB USB 2.0 External Hard Drive, model no. STM303203OTA3E1-RK, for $56.99. An in-cart discount lowers it to $49.99 ($0.16/GB). With free shipping, that’s $9 under our mention a week ago and the lowest total price we’ve seen. Sales tax is added where applicable. This 7200 rpm drive features a 16MB cache.