Once you need to scale, you need that expertise... if I can use RDS, Azure SQL, or a number of other options to manage database services, or other systems without dedicated staff, that buys time to keep the lights on while actual solutions and features are created... an MVP needs to work... And "wasting" a few hundred a month on hosted services while trying to get something working is better than having to spend that time becoming experts on infrastructure, databases, or any number of other systems.

I'm not saying don't optimize, but I am saying that you shouldn't switch infrastructures unless you are saving enough to cover additional talent.