"I want an open source AWS" with $500 budget made me guffaw
In all seriousness, I would probably throw $10 at a project to design and implement a modern turbofan FADEC + all of the certification artifacts.
this literally already exists if you’re willing to maintain your own physical infra, and has for a long time - nothing aws does is that innovative software wise. maybe their managed k8s eliminates a ton of pain, but I dont know. it’s the reliability guarantee + support + not having to maintain physical servers. if youre willing to shirk all that and do it yourself why would you want aws? lol
tldr; was laughing at the xy vibe of the ask