Perhaps at current AWS prices your self-hosting is 3x cheaper.
But thinking about fundamentals, a few years out, why do you think self-hosting will still be cheaper? What is it in self-hosting that economies of scale of AWS/GCE can't crush?
1) They are dependent on Intel or AMD for the higher end processors. This is a $5 billion-per-factory industry. So that is one thing they can't easily replicate.
They don't make that on AWS, in gross revenues. This is similarly true of most hardware inside a modern server. They can make small improvements but they can't magically take over the CPU market or any of the other core components in a 'big way'.
2) Creating all that in-house software automation is complicated, difficult, and expensive. This software isn't a requirement for in-house hosting.
So they need to crush the margins of their supplies [power; bandwidth; hardware] to the point that they can get their own margin on top of that + cover the cost of a bunch of custom in-house software development. For a stable workload...that just isn't going to happen.
AWS isn't going to cut their prices 33% after the largest price cut I've ever seen them make in April, let alone the 67% they'd need to.
Sure, in 10 years, they might manage it. I don't see it happening faster than that.
A cloud provider pays the same as you for real estate, electricity, x86 hardware, and engineering talent,
The only advantage of scale is being able to oversell, e.g. running one customers workload during their peak hours and another customer on the same kit at theirs.
real estate - don't they explicitly look for cheap real estate and tax breaks?
electricity - cloud providers save a lot on electricity by choosing carefully their locations. Facebook built a datacenter in the Arctic, I don't see your average enterprise doing that.
- x86 hardware. They're spending a lot less by having their own custom hardware
- engineering talent. They should be saving by using local talent from elsewhere, not Silicon Valley or NYC wages. IBM does that.
But thinking about fundamentals, a few years out, why do you think self-hosting will still be cheaper? What is it in self-hosting that economies of scale of AWS/GCE can't crush?