Are you claiming that you knew exactly how powerful you needed your machines to be, before you launched? Or are your machines running at 25% utilization which AWS would charge substantially less for?
I'm not making any such claim. I'm saying I built a 24-7 available physical 17-server cluster to operate my startup's needs. I had more capacity than I needed, but at the same expense thru AWS I'd not have enough to operate. At less than the expense of one AWS month, I had my entire environment owned outright. How is that difficult to understand?