"the "super-rich" are racing away from the rest of the "rich" (£50,000-£150,000pa)"
Where did the notion that 50k pa make you rich suddenly come from? I know youre not the first, Corbyn made mention of it.. I would strongly argue that £50k pa does not make you rich its not even double the national average wage (~£28k).
To be clear I dont disagree with your comment, just the dissertation that 50k is rich.. Well off maybe... comfortable definitely, but by no stretch rich.