The standard criteria for bursaries in most schools include things like; both parents should be working, equity should be released from properties, lavish holidays, regular new cars, significant home improvements, 2nd homes etc are not appropriate for bursary holders.
I think you are right that things are different in the south East and LOndon. It is the case that housing is often signifanclty more expensive, so people with a household income of £75k may well less in pretty modest houses and have huge mortgages. The bursary is not therefore subsidising lifestyle choices and allowing recipients to continue to work part time or have holidays or new cars whilst their school fees are funded by the bursary pot. People qualifing for bursaries are expected to have made sacrifices (like those paying full fees often have done too) and even Fred they have done that, to not be able to afford the full fees.
I understand incomes and house prices vary across the country. This is why the incomes acceptable for bursaries varies across the country. School fees vary quite a lot too.
I think it’s right that there is a sliding scale of bursaries. Why should it be that only those on rock bottom incomes qualify to get the help that might allow their child to attend? Those on moderate incomes find that the fees are equally out of reach for them too, if they would need to pay the eye watering sums which can easily be £1.75-2k per month for a day place. They might be able to afford something, but being able to afford £500 per month from a decent salary won’t help if the fees are £2k. That’s why the bursaries are on a sliding scale.
As I said upthread, what still often happens, is that those with reasonable incomes such as nurses, teachers, etc find that even if they get a bursary offer, they still can’t take up the place. Quite often a bursary of £500 per month might be offered….not much help if the fees are £2k per month and you’d still need to find £1500 each month. Most schools just don’t have big enough bursary pots to offer big enough bursaries to the numbers who apply and make them oversubscribed. The higher amounts are reserved for those on extremely low incomes and those who are the top performers isn’t he entrance exams are gifted in another area. So, your typical bright but not brilliant child from a family with a £75k income in the south east isn’t likely to get a bursary big enough to make the difference, if they do apply. And those families with £75k may well live in a 2 bed terraced house with a mortgage of £2k per month and have 1 camping holiday over year, with both families working. A bursary would not be allowing them to continue an extravagant lifestyle.