When this coin was minted in 1971, it could buy a lot more than it will today.
I will never understand world economies. Why does the price of petroleum go up and down? Why does the stock market dive when there is a the slightest whiff of a rumor about some economic change, even if it is fully unsubstantiated? Why do the supermarkets drop prices on staple foods all at the same time when if they kept the prices higher, they would profit more?
I think the real answer is that no one knows except God.