Let the hive mind of Engadget get that for you.
"I just switched to Sprint from Verizon about three months ago for the Pre. Then I went for the Hero about a week ago. Now, I miss my hardware keyboard and am thinking about switching to the Moment. I am still able to switch back to Verizon if I want and get the Droid when it arrives. Should I just trade up to the Moment when it comes out, see if I like it, and if not switch to the Droid? Or something else entirely? Help!"
I daresay that another couple of reasons why we get so badly gauged by pricing in the UK is that we have a much higher cost of living generally and that the UK is a far smaller market. UK retailers don't have anywhere near the buying power of their US equivalents so don't benefit from the same economies of scale.