@MargotBamborough I can give you an example from my own life, where I do know the variables:
I have a child with adhd- I chose to have him assessed privately, and have been paying privately for his medication and psychiatrist reviews.
This cost around £4000 upfront, and between £120-£170 a month.
After paying this I am very short of money at the end of each month.
However-
I had the opportunity of doing this, it was a choice that I made, and I have something to show for the money I spent- a well supported child.
My best friend has a child who equally needs to be assessed but because she has a lower income, she doesn’t have the option to pay privately.
She hasn’t spent the money I have on assessments and medication, and she is still short of money at the end of the month.
So- yes, at the end of the month we are both short of money BUT in my case it is because I had money and chose to spend it on something, in her case it’s because she doesn’t have the money in the first place.
If you have £58 left at the end of the month after you have paid for your house, car, phone and holiday you have greater spending power than someone who has £58 left at the end of the month but can’t afford a mortgage, a car or a holiday.