For the low price of 59.99 you can have the 11 year old Black Ops 3, or maybe you want to save some money and buy the 15 year old MW3 For 39.99

Digital game store breaks traditional supply/demand curves. Their supply is functionally infinite.

It definitely has happened, the Ford model T went down in price by more than half from $780 in 1910 to $290 in 1924.

https://en.wikipedia.org/wiki/Ford_Model_T

Nothing like that is happening here. This is a move to reduce competition, which has never lowered prices.