For a medium size biz, I'd probably still recommend using GKE or EKS. A smallish EKS cluster of a few nodes will cost <1k a month for everything, it's fully managed so you don't need to pay anyone except for the initial setup.
Otw the cheaper operational cost would be to setup a few hetzner servers and manage your own infra via kubernetes or docker/ansible runbooks. But you should budget a few days each month for maintenance and general support, plus you'll need someone skilled in server maintenance to set it all up (becoming a rarish skill these days).
If on a ramen budget, you can set it up and let it rot until everything breaks, then migrate to EKS. :)
Otw the cheaper operational cost would be to setup a few hetzner servers and manage your own infra via kubernetes or docker/ansible runbooks. But you should budget a few days each month for maintenance and general support, plus you'll need someone skilled in server maintenance to set it all up (becoming a rarish skill these days).
If on a ramen budget, you can set it up and let it rot until everything breaks, then migrate to EKS. :)