The breakeven rate on developer hardware is based on the value a company extracts not their salary. Someone making X$/year directly has a great deal of overhead in terms of office space and managers etc, and above that the company only employees them because the company gains even more value.

Saving 1 second/employee/day can quickly be worth 10+$/employee/year (or even several times that). But you rarely see companies optimizing their internal processes based on that kind of perceived benefits.

Water cooler placement in a cube farm comes to mind as a surprisingly valuable optimization problem.