It depends hugely on your cost of staffing. Also, there is not only aws vs on prem. There are solutions in the middle where you don't have all of the AWS serv

It depends hugely on your cost of staffing. Also, there is not only aws vs on prem. There are solutions in the middle where you don't have all of the AWS services but price is much lower. I've seen very average businesses spending 1mln per year in AWS for, really not much. IMHO most mid businesses would be better off renting servers and having some staff maintaining them.