Not the parent, but, I, too, have done the cost analysis, at much smaller scale.
And, yes, all-inclusive, AWS is 1.5x-10x more expensive than commodity hardware, depending on how poorly optimized AWS's hardware choices were for the particular workload and the commercial datacenter market at the time.
> What about the salary of the person
In general, I've found the need for the quantity of "person", bizarrely, exaggerated.
> The cost of spare parts?
Included, and it's low. Is this another aspect that's exaggerated?
> The cost of downtime when hardware breaks?
This is identical to the cost of downtime when AWS's hardware breaks.
What about the salary of the person who maintains all of that? The cost of spare parts? The cost of downtime when hardware breaks?