Buy.com via Rakuten Shopping offers the Fantom GreenDrive 2TB eSATA / USB 2.0 External Hard Drive, model no. GD2000EUS, for $99.99 with free shipping ($0.05/GB). That's the lowest total price we could find by $16. This "green" drive purports to draw up to 40% less power than other, non-green units. It features a 32MB cache.
Note that Amazon charges the same, however stock is very limited.