Boots, both online and instore, have "selected toys" in a 3 for 2 sale and fortunately, that includes all of their stocks of Lego!
Some sets are sold out (Toy Story sets for example) but they do seem to have quite a lot left, so if you wanted 3 Battle of Endor (8038) sets, for example, but only wanted to spend £150, now's your chance!
Click here to see what they have in stock.
NB : I don't believe this sale is in place of the 3 for 2 they usually have in September. That is a sale on all gifts, in the run up to Christmas. You'll most likely be able to get the summer wave of sets on sale then! This sale doesn't include any summer wave sets.