So you are saying when I am able to configure postgres I can earn a $300K salary? Sorry but this is utter bullshit.
BTW this isn't a criticism - just an observation - cloud has been around now for that long. Still feels "new" to me :D
So, speak for yourself.
did you ever try to configure postgres cluster with failover, and also backup, recovery, monitoring?
Also, I said it is hardest part, but you still need to know your load balancer, security, monitoring, updates, app deployment and configuration stuff.
Yes, this is big chunk of knowledge which in my understanding you don't have, and the topic is that this all worry free replaceable by AppEngine+CloudSql for $100/m if your traffic/data are not very large.