I wouldn't expect to see a huge difference between the two. There will be a difference, that's for sure.... but if it really was huge, everyone would be going to the US, and all the UK schools would be closing down because they had no students.
The difference is just about right that many people can justify spending a little more to do their training in the UK. The reasons behind the justifications will be varied, but a couple of obvious examples would be so that they can stay near family and/or friends, or keep their existing job while they're training.
FFF
-----------------