I'm not really convinced by the argument regarding value-based pricing, because that's just not how markets work.

The clearing price (in this case, of labor) is based on demand AND supply; it has nothing to do with how much value you bring to the table. Yes, it's true that maybe writing some piece of software will save some company ten million dollars per year. Should you get one million dollar for writing it? Maybe not, if I can find someone charging 60K to develop that same piece of software.

There is one way to do that with software, though: royalties. It's used for middleware for games and movies. But it's more a risk-management tool for buyers than a sure path to profit for providers (i.e. with royalties you limit your losses if the game or movie does poorly).