"So while we get a lot of attention here may I ask views on why some flight schools like Stapleford in essex advertises £25,000 for ATPL paid up front or £30,000 pay as you go, why then do other schools charge double?"
You are paying extra money, for school x, because of the 'name' of the school. I wouldn't see it as anything else. Bottom line is you get the same thing. Whether people can justify paying an extra 20 to 30,000 on just the name is entirely their choice. School x will spend a fortune on advertising and marketing.
It is the same situation with US schools, you can get the same ratings in two completely different ways - FBO or the more expensive 'academy'. The planes at the FBO will be older, the schedules may be a bit tighter - but this is counter-balanced by the cheaper ratings..