I think the 60 v 75 thing is confusing. I would make it $70 per hour/device ($490) or $75 per hour/device ($525). Or hell...$95 or $125 an hour (what i think is our industry standard).

I think its fair to estimate 1 hour per device. If you count up procurement/unboxing/removal of boxes/installation/setup & testing etc you are usually around 1 hour per device.