Amazon have just dropped the price of the 3DS to £174.99, but they are also offering bundle deals to include one of the following games for only £10 extra:
Super Monkey Ball 3D (usually £21.79)
The Sims 3D (usually £29.99)
Rayman (usually £32.97)
Ridge Racer 3D (usually £27.65)
Ghost Recon: Shadow Wars (usually £29.99)
In addition, you can get a free set of screen protectors (value £4.99) and a case for £5 (usual price £7.99 or £9.99 depending on which one you choose).
With the prices CEX are currently paying for these games, the net price of the console itself comes down to between £169.99 - £162.99, cheapest yet.