They're selling off 100019 (the Star Wars Rebel Blockade Runner) at £50 instead of the usual £135. Some of the boxes are a bit battered, but a pristine box is hardly worth £85.
There are plenty of other sets in the sale, including some of the rather expensive pre-school play sets at less than half price.
Oh, and Argos are selling the Adventurers' Oriental Castle for £35 - that's half price, too.
Richard