bang for the buck
- (idiomatic) Efficiency; cost-effectiveness; value.
- Do you think he would get as much bang for the buck out of a fancier, more expensive car?
Vulgar World War II GI (general infantry) slang for liberty activities of a sexual nature. Seeking the best bang for the buck, i.e., maximizing sexual gratification for the least amount of money, thereby saving his money for other purchases (drink/food).