Well, people are willing to pay that much for tamagotchis. I paid a lot for mine, and I've been playing with them for over a month. I think it was worth it considering I would still be drooling and waiting anxiously for the US debut, but not everyone feels the same as I do.
Yes, the Keitai is pretty much the V2 of Japan. Ours cannot connect to Cell Phones, so we got a V2 instead to compensate -- a Tama that has most of the features of the Keitai.
Nope, I have no idea when the Minis will be released in the UK or the US. There hasn't been much information about them at all from Bandai or any other corporation.
I think the reason why the US V2s were released in the UK is because they needed some extra stock to suppliment the Supply. So many people wanted the Tamagotchis that there were just way too many people, and not enough Tamagotchis to supply them. The US wasn't supposed to debut theirs until months after, so I'm sure they just assumed that they could suppliment some of the avaliable US stock into the UK. Just my theory, but I think it pretty much fits the bill.