I don't think it would literally be $16 million to do a 2d RPG, but I could see it being maybe 2-5 million, with a small but experienced team.
Like I said before, it boils down to time- and while technology has improved, and some things are much easier to do, it's still not THAT much easier. A full featured game takes a long time to make. Even if you start with a pre-made engine, you still have to break down the whole game into smaller tasks as ask "how long will this take?" With a high number of features, the answer is always "a long time", and usually ends up taking longer than you originally expected.