Regret ordering.

How so?
It is ~$3000 more than the base PHV(Prime) in the UK, but is a little less than the top trim.
All-New Prius Plug-in | Plug-in Hybrid | Toyota UK
The list prices include the 20% VAT. Without that, it is similar in price to the XSE in the US. The GT* Golf has always been a higher priced trim.

Even without digging into the feature differences, I wouldn't call the price difference crazy.

 

Fair enough. I was comparing what I paid for my SE in the US to what the GTE price in British pounds (including VAT) would convert to. That difference is still around $15000. Without VAT it shrinks to $8000.
I did not realize that the SE is quite a bit higher in the UK.