As dicki says, subjective. If I ever did find myself earning £150k, I would probably cease to call it rich, and say that I was doing OK, someone on twice that, now that would be rich. And of course, "rich" is only partly about income. It is about wealth. Not working? Income zero? Got a million pound house and a £100k p.a. pension? Yeah, you're doing alright.
As dicki says, subjective. If I ever did find myself earning £150k, I would probably cease to call it rich, and say that I was doing OK, someone on twice that, now that would be rich. And of course, "rich" is only partly about income. It is about wealth. Not working? Income zero? Got a million pound house and a £100k p.a. pension? Yeah, you're doing alright.