Staples offers the Western Digital Elements 2TB USB 2.0 External Hard Drive, model no. WDBAAU0020HBK, for $79.99. With free shipping, that’s $0.04/GB and the lowest total price we could find by $3. (It was $10 less two weeks ago, since expired.) Sales tax is added where applicable. This drive uses GreenPower technology to reduce power consumption by up to 30%; it runs at 7200 rpm.