Who is managing these two dedicated boxes at OS and app level. Who is managing the networking of these boxes, including a non-internet accessible network subnet and a an internet gateway to let a white listed developer host box connect to a dev instance of database with some sample data?
Using secrets manager, which handles key rotation seems to work great on AWS, how does this work on the rented boxes.
Who sets up the slave, confirms replication is current to slave etc.
Who does the backups of all of this (in case of a DROP table).
I used to do things the harder way with rented boxes. BUT every-time someone tells me oh - just rent some boxes and you could do X much cheaper I roll my eyes. X is always a massive subset on security, durability with a massive uncounted overhead in other areas (waste of time).
If you mean 'I ticked the multi-az box' that is only in the even that the AWS datacenter crashes - it will move RDS for you to another zone. If you have services that cache ip addresses from DNS, you will need to rediscover the database.
AWS is expensive but for a company it's very cheap for the problems they avoid completely.