I don’t think cloud cost is anywhere near as much as the cost to build a semi-decent HA/DR system and the devops process around it. Every minute the site is down it’s real monetary loss for most startups. It also takes time and energy away from building features. I have done both bare metal and cloud in two different startups. (This assumes you can’t afford to lose data or be offline for extended periods of time).

Here’s what you’ll need to setup and run a single database :-

- Installation script and infra provisioning. You need a repeatable way to do this with as little manual intervention as possible and I can swear it never just works.

- Backup and recovery scripts and associated monitoring

- Replication setup, monitoring and debugging. It will break often.

- Monitoring for infra - CPU, memory, network. There’ll be unforeseen spikes and random slow downs and a whole bunch of slow queries you’ll debug on a regular basis.

- Security - users, permissions, auditing. Both machine and database. Regular password rotation and firewall rules. Ability to off-board users.

- If you survive all this, being able to scale up. And I mean just vertical scale up will take you far but you cross that limit, you now suddenly have to deal with sharding or partitioning.

So when I joined a new startup and we were building it all from scratch it was a very easy decision to go with the cloud. We spent $3500 a month. Not a lot but nothing compared to the salaries and marketing spend.