Hi Bravo-Papa,
I fly out of Biggin.
The airfield is relatively expensive to operate from, and yes, Cabair are expensive too.
I learned with Cabair at both Redhill and Biggin.
Although Cabair Redhill is now defunct.
What you need to watch at Cabair (other establishments may be similar, but Cabair is the only one I have trained at and am thus qualified to comment); is that you may get a really great instructor, or you may get a really crap one. And your learning experience/time to test/wallet will benefit/suffer accordingly.
And it's not always easy to swap from bad instructor to good.
Wherever you go, try to find out which instructors are the busy ones - i.e. those that are held in high regard by the students.
Speak to them yourself - interview them. Don't just let yourself get assigned to one. And review after a few lessons if you feel ok with the one you have got.
Listen out to other students/their converstaions with their instructors on their way to/from the aircraft.
It's also good to have the odd lesson with another instructor - a different teaching style is refreshing - and they may pick up good/bad points about your flying.
Redhill is much cheaper than Biggin (although occasionaly it gets waterlogged) and there is another operator on the site (can't remember the name but its on the cafe site). Try there.
I am not convinced about going to US, particularly if you are going to be flying in the home counties.
The weather is completely different, and you will need to understand the busy and restricted airspace restrictions - neither are something you can pick up in the US.
I wouldent have wished to take my early post-test steps in airspace with which I was unfamiliar.
And other contributers are absolutely right - NEVER pay for a course up front - however good the deal seems!
Hope that helps.