heh, right.
for example, I'm in the process of buying a new CNC machine this summer.. it's about 11x the cost of a 12core Mac Pro.. rent on my shop is like buying a Mac Pro every month.
the computers are the cheap part of the business equation.
It's only the hobbyists who hang out on Macrumors bitching about the Mac Pro 6,1 who find it expensive because they are paying out of their own pockets. In fact out of the bitching seems to be done by those who never bought a new Mac Pro & have only been able to afford a used system now the prices are lower.
If you are earning money with your Mac Pro (or car or plotter or camera or CNC machine) then $100-200/month or more is peanuts compared to the income that it should be generating.