Anything equally difficult should have equal payoff. Apparently. Clearly, this is not the world we live in.

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(producing utility and its bastard cousin, money)

[...]

As instrumental rationalists, this is the territory we want to be in. We want to beat the market rate for turning effort into influence.

You are speaking my language. +1. I appreciate your style.

Reality is imbalanced. Video games and roleplaying games give people the impression that all options have pros and cons, and are roughly pretty equal: the Warrior is just about as powerful as the Wizard is just about as powerful as the Rogue. Real life doesn't work like this: intelligence and charisma are overpowered, and sometimes humanity finds exploits in the rules that let us send messages nigh-instantly around the world. (And when we do, reality doesn't fix the exploit; rather, society changes.)

I wish there was a table top game where everything was completely imbalanced and players are encouraged to break the mechanics as hard as they can (but be careful, because society at large may adopt whatever exploits are found, and the antagonists are trying to become really powerful too).

This begins to suggest the sunk cost fallacy may not really be a fallacy (sometimes).

I'm not sure I follow. Not all past costs are sunk, surely. But, in your example, if writing a second book gives you more influence than learning plumbing, then I don't see where the "sunk costs" (e.g. that you wrote a book once) come into the equation.