Of course £150k is a lot of money. But it is easy to spend it - I know that sounds obscene to someone struggling on a fraction of that. But it is true that everyone lives to their means, and if you are earning that sort of salary, you generally have expenses that are seen as luxuries but to you are essential - who is going to work 14 hours days and weekends, and then come home and do their own cleaning and DIY?
And the big house is often an investment: if you are earning over £7k a month, servicing a large mortgage is a decent way of investing into your family life, and with property having soared in the last ten years, it has been a sound investment.
To the OP - I think that if you are earning a salary of 150k or more, you are paying an enormous amount in tax already: a lot of your income at 40%. And those of us on PAYE get hit very hard, as there's less option for hiding income or restructuring it into more tax efficient payments. So I think a fairer system would be a high rate of tax for ALL high earnings, not just salaries on PAYE.