around one year ago I've evaluated how much it will cost me to run DB (MYSQL) server on RDS, taking current server (one of) as example.
If my memory serves me well, for medium sized DB of 2TB/160GB RAM/20+ cores, it was something like 2000$/month on RDS and around 230$ on Hetzner (with AX161, actually having 2x3.5TB NVMe disks and high iops capacity and 32c/64t EPYC CPU).
That project was never been in AWS/"cloud" though, so savings are made in upfront.
I have not done any traffic calculations, though - I actually forgot that AWS can charge you for that as well.
If my memory serves me well, for medium sized DB of 2TB/160GB RAM/20+ cores, it was something like 2000$/month on RDS and around 230$ on Hetzner (with AX161, actually having 2x3.5TB NVMe disks and high iops capacity and 32c/64t EPYC CPU).
That project was never been in AWS/"cloud" though, so savings are made in upfront.
I have not done any traffic calculations, though - I actually forgot that AWS can charge you for that as well.