I dunno, it does sound like significant work and way outside my (and most devs) area of expertise. I can definitely supervise a managed RDBMS (like RDS) by myself without help on the side even though I am no dba.
A mismanaged VPS is downtime and churn, a mismanaged DB will insta-kill your business if you have unrecoverable data loss. I would definitely use a managed solution until I can get a dedicated person to babysit the DB, but I would consider managing a VPS myself.
There's no need for a dedicated person. A single operator can easily manage dozens of DB instances unless your needs are extremely complex. Managing these kinds of things are serviced trivially available on retainer.
A mismanaged VPS is downtime and churn, a mismanaged DB will insta-kill your business if you have unrecoverable data loss. I would definitely use a managed solution until I can get a dedicated person to babysit the DB, but I would consider managing a VPS myself.