> But my Kubernetes Cluster on AWS can handles this for only 30.000$ a month
A k8s cluster for something like that wouldn't cost anywhere that amount, plus you would get the advantage of being able to deploy your app in multiple availability zones. If you don't need k8s features, there are definitely simpler options that will give you redundancy and won't break the bank.
I only used a MacBook cause it was faster to ask IT for one than to have my ticket processed and approved by the cloud and security team which both required a write up on why I need a vm and what justification I have for needing it. Meanwhile IT is like "here you go".
A k8s cluster for something like that wouldn't cost anywhere that amount, plus you would get the advantage of being able to deploy your app in multiple availability zones. If you don't need k8s features, there are definitely simpler options that will give you redundancy and won't break the bank.