Amazon EC2 M1 Mac Instances
It’s an interesting look at AWS pricing since the cost of the M1 Mac Mini ($699) and it’s power consumption (avg 26 watts) are known. Based on hardware costs (significant) and power costs (insignificant) you’re looking at a hardware ROI at about 6 months from the $.65 per hour price. AWS has an estimated 60% gross profit margin, so from there it’s probably possible to estimate some other interesting things about their costs, utilization rate and 
depreciation schedule.Edit: Sorry, my napkin math assumed a unstated utilization rate of 40 hours per week, but that’s not a great assumption due to the 24 hour minimum. Still, some proportion of machines will be idle, though 75% idle seems like a bad guess.