John Lewis, instore and online, have reduced the price of this set to £19.95, which is a 50% discount. You can have it delivered for prices starting from £3, or if you live near a store, you can pick it up from there for free.
It appears that John Lewis also have 50% off a few other sets, those being :
Sadly, 7573 : Price Of Persia – Battle Of Alamut is Out Of Stock (at least online)
They do however have 25% off various Racer and Creator sets.