A friend tells me that his son has a job "Not too well paid only around £23000" Age about 24.

At the sons age I was married, 2 children, had a mortgage and was looking forward to earning £1000 a year.
I reckoned that at £20 a week I could live reasonably, pay the bills, bring up the kids
£1000 a year was the benchmark where most of my friends thought that they were comfortably off.

Who is in fact any better off now at £23K than they were then at £1000pa.and in what way?

Gunnerpat

This sounds like a homework question.

All it takes is a few key materials to start the rise in prices - energy related ones are big, land, lumber - anything based on scarcity as demand rises. Products and services and labor follow suit.
Not everything goes up and up. Electronics go down and down. Imported foods go down but also go up, depending.. and we all can eat a wide variety even in the winter. We didn't have a fresh vegetable all winter..

Think about what your dollar bought when you made 1,000. A car might have taken a year's salary, right? It still can, but now there's a huge variety of prices, easily 3 fold in the normal range. Same with real estate. You can buy a house for very little in a depressed area, or 20 times that, and be in normal range.

Your last question isn't answerable. You didn't even tell us how old you are so we don't know when you were 24.