Salisbury Cathedral from the Meadows

I was reading of the sale of this picture by John Constable (1776-1837) which has just sold for £23 million.
This is staggering, no painting should be sold for this amount of money!.......should it?
Dear Constable would be amazed; he only sold 20 paintings in England in his life though he sold many more in France:
He refused to be tempted to try and sell his paintings by going overseas for a while saying;-   "I would rather be a poor man in England than a rich man abroad"
He was a poor man always and lost his much loved wife to tuberculosis when she was just 41 years old, he was intensley saddened and wore black for the rest of his life.    He cared for their 7 children alone.