If you have more than a single child of school age, £90k in London is not that much. Two kids at a private school in Northern England will run you £30k, I imagine in London it will be a tad more.
Never mind private schools, housing costs go through the roof if you want them to have their own room or, god forbid, a garden. Not to mention nursery fees if you both need to work to cover the mortgage and bills.
I explitliy mentioned: for one person. Of course, if you want to raise a family with private schols and a big house in the middle of London, that won't work. But let's not twist my words here.
