> (Aside: should the guys who drive an armored car that carries millions of dollars in bonds get paid more than the guys that drive an armored car that only carries thousands of dollars in cash? Does the amount of money handled change the difficult of the work?)

Possibly, yes. The amount of money handled might affect the likelihood of a heist, and the required preparedness of the robbers. Which in turn requires more skilled drivers facing a higher risk.

https://www.youtube.com/watch?v=lsu6AhYzG_4

That aside was an unnecessary bad tangent which undermines the point.