Found at Chester Road, Manchester Branch (currently a clearance store whilst renovating?) last week.
This particular model is an older model (G20 is the newer range) but this is cheaper than elsewhere for example:http://shopping.kelkoo.co.uk/ssc-127101-panasonic-42g10.html
shows £649.99 @ Amazon
Why not also try to get John Lewis to price match for those not living locally.
Apologies re the picture quality (mobile phone not up to scratch!)