“Bang for the buck” means getting the most for the amount you have paid.
The phrase is a Cold War military expression with sinister suggestions of atomic and other explosive devices.
Before the Berlin Wall came down in 1989, the United States and its allies in the West were engaged in a series of confrontations and skirmishes with the former Soviet Union and its satellite states.
“Bang for the buck” described how efficiently the American defense, and offense, budgets were being spent.
As poet and playwright T.S. Eliot (1888-1965) wrote in “The Hollow Men” in 1925,
“This is the way the world ends/Not with a bang but a whimper.”