Birthday of Vincent van Gogh: what can we learn?

Today is the birthday of famous Dutch painter Vincent van Gogh.

He died poor. He managed to sell just one of his paintings during his life, for little money.

However, after his death, in a cruel twist of economical mechanisms, he became an artist off whom some people made very much money.

Van Gogh was not untypical in this. What can we say about relationships between art, money, and poverty; art, peace, and war; etc? See here.