Finding someone who can setup Postgres wal archiving and replication in only 6 hours per year is surely costing you 600$ in additional salary per year. I don't think your argument holds any merit at the level of hosting costs we talk about. Also as someone who does host stuff on a dedicated machine too, have you looked at what is involved in upgrading to say Postgres 9.3 from 9.1. If you have single server you will just not do it unless you are also big into Russian roulette.
Finding someone who can setup Postgres wal archiving and replication
Your $50 database doesn't need that. A simple backup works fine for a great many people.
I don't think your argument holds any merit at the level of hosting costs we talk about.
In order to match the performance of a measly $50/mo dedicated server you'll pay in the ballpark of $1300/mo to Heroku (16GB DB + 16 "dynos"). In between these two figures there's a lot of merit to be had.
have you looked at what is involved in upgrading to say Postgres 9.3 from 9.1
Yes, you stop the db, run pg_upgrade, and start the db.
But as you correctly state, most people in this bracket have no reason to upgrade their database software ever.
