I think you'll always find extremes Purple but in general I find that the prices, once VRT is factored in and based on the current exchange rate, are about 15-20% more on average here. What you really need to weigh up is whether or not you are happy to deal with any issues should they arise as it's not very practical to head back over to the UK to get them looked into. You also need to factor in how to get rid of your old car as trade ins are not as welcome in UK, nor will you get much for it. Ideally if you can sell yourself before heading over, or shortly after, that would see the best savings here.
Buying from the UK certainly is back in consideration now alright though. Personally I'm hoping to use it as a bargaining tool in getting the price down a bit with local dealers but if that fails then I'll be looking to the UK again.