Just had a look at that link however, from what I can see, all the prices listed are the same as what you would pay on Apple's website.
Personally, I still think that getting the 42mm Space Grey Sports model, for £280, from my friend at Apple, is probably gonna be my cheapest option.
I would say that the ONLY thing holding me back is this: Am I crazy to buy one now (looking to order it next week), knowing that Apple's March event is so close (March 15th if rumors are correct!) where they will potentially be announcing a new model of Apple Watch (my views on this are in my original post!) ?!
I actually currently own a Pebble Time Steel and I gotta say that I do love its looks but it is seriously limited on iOS - can't reply to texts or calls (literally, all you can do is dismiss notifications. You cannot act on any of them) and this is the primary reason why I want an Apple Watch. I want to be able to experience what it is like to have full 100% functionality with my iPhone 6!!
The website shows the price listed on that 4 UK retailers during the day. So, if they don't have any discount, the price will be the same as on Apple's website. I've got mine when the prices was £50 cheaper in Currys than on Apple's website.
I've heard they will announce new straps for Apple Watch, not a new version. But, using it from 3 months so far, in my opinion, there are some improves they need to apply, for example, the apps takes long time to open on the watch. Lack of really essential apps to use.