The cost of a person: fixed plus variable
Two engineers on the same salary. The AI bill is the part that varies.
Engineer A
Thinks first. Fewer models. Few agents left running.
AI bill · variable
Salary · fixed
Engineer B
Bigger models, agents left overnight, regenerates instead of thinking.
AI bill · variable
Salary · fixed
Same salary, very different cost. Sooner or later someone asks whether it paid for itself.