It sounds like you're agreeing with the OP. Heroku is a great deal for people just starting out, somewhat at the expense of those who have already grown larger

It sounds like you're agreeing with the OP. Heroku is a great deal for people just starting out, somewhat at the expense of those who have already grown larger. His strategy seems sound-- use Heroku at the beginning, then if and when it gets unjustifiably expensive, switch to AWS.