Managed services are often the right call. The bill that surprises you is rarely the instance — it is egress, backup retention, and the version you are not allowed to stay on.
We recommend managed databases regularly. Running your own is not a virtue in itself, and a small team has better things to do than tune compaction. But the comparison people make at decision time usually leaves out three lines.
Egress
Cross-zone and cross-region traffic is metered, and replication generates a lot of it. A three-zone highly-available setup can move more bytes between zones than it serves to users. That line is often larger than the instance cost, and it never appears in the pricing page example.
Backup retention
The included retention is short. Keeping thirty-five days, or a yearly snapshot for audit, is usually billed at storage rates that are several times the equivalent object storage. It is still worth paying — but it should be in the comparison.
Forced upgrades
Managed means the provider decides when a major version reaches end of support. That is largely a good thing; it also means an upgrade window you did not plan, on a date you did not choose. Budget the testing time annually rather than treating each one as an incident.
How to decide honestly
Model both options over three years, at your projected volume, with those three lines included, and add the engineering time each requires. Sometimes managed wins by a wide margin. Sometimes it does not, and the difference pays for the engineer who would run it.