Re: London to Geneva (cost of living)
It has a lot to do with perception and culture too. Several of my 6th Formers, and friends' children, who were very bright - were encouraged to apply for Oxbridge. many were invited to visit there, and for interviews- but they thought both Oxford and Cambridge stuffy and stilted, and the courses not as exciting as some other universities, and too much based on classics, and preferred to go elsewhere.
Not sure where you live in UK about the 1- 2 m houses in 'good' catchment area. Are you in Surrey perhaps? In most other areas you can buy a good house with access to 'good' schools, for 'normal' prices. Mind you, the shananigans some people and relatives got up to to beat the catchment area system was staggering. They got all religious all of a sudden (and it didn't last once the kids were in the school) - some relatives even bought a flat for a daughter and kids, so they could pretend to live there for a while (a few nights here and there) and get into the school of choice- then the parents re-sold the flat at a good profit a year later when both girls were registered at the school, etc.
This of course also happens in Geneva and Zurich (perception and/or reality of 'good' and 'bad' areas, with their schools. Only difference is, here you have no choice at all, the Council allocates a school to your children, that's it. I am so glad I grew up, and now live, in a rural area where housing is totally mixed- and where all kids go to the local schools, with no provision whatsoever for private schools - in the whole of our Valley, I know of only 1 child who goes to a boarding school, same where his father went and his grand-father- and even he stayed at the local school until the 6th Form. Some of the people who send their kids to the local school are professionals and major business people- and they truly believe growing up in a very mixed environment is a/ the best for their child and b/ the best for society as a whole.