This deal is a bit of work and the cheaper price is only if you have an old dishwasher to trade in
John Lewis are selling it for £459 delivered but Comet are doing the same price with 10% off at at the minute (£413.10)
JL will price match Comet if you email them the details via their price match page:http://www.johnlewis.com/help/nkupricematchform.aspx
JL are also doing £50 trade-in on your old dishwasher so you can get this for a possible £363.10
You can download the form for the 5 year warranty directly from the JL website under the 'Guarantee' section
Hope this helps someone!