£107.99 seems a decent price for a 3TB external hard drive (3.6p per GB). You will need to have a free delivery account to get it for this price. Google it if you don't know how to get a free delivery acocunt from Scan.
This is currently on the "Today Only" offer at Scan. Clicking the link will automatically add the item to your basket at this price.
Do not add the item to your basket from the product page, it must be done by either clicking the "GO TO DEAL" link in my post, or by finding the item on the TODAY ONLY page here: http://www.scan.co.uk/todayonly/index.aspx