There was a piece in the news a couple of years back trying to dispel the idea that private school teachers were paid more than state teachers, based on the idea that they weren't getting pay rises and were working longer hours.
I think this may have some truth where fees have risen with or above inflation but teachers salaries have been kept on hold - whilst state teachers have had a small but inflation linked increase. However, for the headline making "uber" private schools this appears not to be the case. Of a small group of private schools, those schools are few in number (30-40 maybe?).
Statistics are dangerous things and I'm going to be guilty of making comparisons between apples and pears, but I think the "average" for state and private is very different to the "uber school" situation.
For example, the "average" state secondary schools national salary for a full time equivalent teacher was, based on the Nov 2013 DoE data:
£38,521 (FTE state teacher average, increase of inflation minus 1%?)
My local comp in central London pays teachers an average of about £41k so the "London" weighting is not much.
Compare to a well known west London "uber school" .....
The average for all staff (including TAs, kitchen etc) was £43,660 (up from average of £41,940 last year an increase of 4%), but let's try to get the teachers in focus.
There are 112 "educational staff" of which 30 (over a quarter) are paid over £60,000 - an increase of 5 from the year before (through hiring and pay rises).
Twenty staff are paid £60-70k, six are paid £70-80k, two are paid £80-90k, one £100-110k and one (the head I assume) paid £170k. The average amongst this top quarter paid is £73k, almost double the national average.
Looking at it another way:
State schools spend an average of £5,865 per pupil in England and £8,641 in London. This has probably risen by about 10% in the last 4 years.
The same "uber school" in London spent £20,760 per pupil, a 4% increase in 1 single year.
Attracting teachers that will keep the small list of "uber schools" in their esteemed positions takes a lot of salary and benefits and a lot of investment in infrastructure. This is where the "cream of the crop" are tempted. Thank goodness there are many who sacrifice such offers to stay in the state system.