Spotted this in my local store so not sure whether its nationwide. Amazon are charging £47 for the same (http://www.amazon.co.uk/Seagate-Expansions-500GB-External-Desktop/dp/B0020FVKO8/ref=sr_1_1) and reviewers have given it 5 stars.
Seagate external desktop drives provide extra storage for your ever growing collection of files. Instantly add space for more files, consolidate all of your files to a single location, or free-up space on your computers internal drive for improved performance.
Setup is straight forward, simply plug in the power supply and USB cable and you are ready to go. It is automatically recognized by Windows®, so there is no software to install and nothing to configure. Saving files is easy too, just drag-and-drop.
Its not just easy to use its fast and energy efficient too. Enjoy fast data transfer speed with USB 2.0 connectivity and 7200 RPM drive performance. Built-in power management ensures energy efficient operation.