I've ordered a Sony STRDA2400ES for £389 delivered from Priceless Electronics. This is a good £30 cheaper than i've seen it elsewhere - is it likely that this isn't UK stock and will not be the UK spec?
It's possible it might be a 'grey import' from mainland Europe, but there's no way of telling unless you've got the serial number and can check with Sony UK. What did Priceless say when you asked them? If you're planning to use it with Sky TV, then make sure it's one of the ones that's been modified to accept multichannel audio via the optical connection rather than HDMI.
i think it will be ok as i got the same receiver from stone audio for 400 pounds plus delivery and they confirmed to me that they were all from sony UK so i would hope that 20 pounds cheaper would still be a UK model.