How expensive is making humans vs. their utility? Is there something markedly more efficient that won't complain or rebel if you treat it poorly?

Yes. The nano bots that you could build out of my dismantled raw materials.There is something humbling to realise that my complete submission and wholehearted support is worth less to a non-friendly AI than my spleen.

How expensive is making humans vs. their utility?

Utility for what purpose? If we're talking about say, a paperclip maximizer, then its utility for human beings will be measured in paperclip production.

Is there something markedly more efficient that won't complain or rebel if you treat it poorly? How efficient/useful could a human be if you treated it well?

It won't be as efficient as specialized paperclip-production machines will, for the production of paperclips.

Are you willing to accept that premise and see if you can draw any helpful conclusions or give any helpful advice?

Yes, but you're unlikely to be happy with it: read the sequences, or at least the parts of them that deal with reasoning, the use of words, and inferential distances. (For now at least, you can skip the quantum mechanics, AI, and Fun Theory parts.)

At minimum, this will help you understand LW's standards for basic reasoning, and how much higher a bar they are than what constitutes "reasoning" pretty much anywhere else.

If you're reasoning as well as you say, then the material will be a breeze, and you'll be able to make your arguments in terms that the rest of us can understand. Or, if you're not, then you'll probably learn that along the way.

Comparative advantage explains how to make use of inefficient agents, so that ignoring them is a worse option. But if you can convert them into something else, you are no longer comparing the gain from trading with them to indifference of ignoring them, you are comparing the gain from trading with them to the gain from converting them. And if they can be cheaply converted into something much more efficient than they are, converting them is the winning move. This is a move largely not available to the present society, hence its absence is a reasonable assumption for now but one that breaks when you consider indifferent smart AGI.

The law of comparative advantage relies on some implicit assumptions that are not likely to hold between a superintelligence and humans:

The transactions costs must be small enough not to negate the gains from trade. A superintelligence may require more resources to issue a trade request to slow thinking humans and to receive the result, while possibly letting processes idle while waiting for the result, than to just do it itself.

Your trading partner must not have the option of building a more desirable trading partner out of your component parts. A superintelligence could get more productivity of atoms arranged as an extension of itself than atoms arranged as humans. (ETA: See Nesov's comment.)

A sufficiently clever AI should understand Comparative Advantage

And a sufficiently clever human should realize that clever humans can and do routinely increase the efficiencies of their industry enough to shift the comparative advantage.

It really doesn't take that much human-level intelligence to change how things are done -- all it takes is a lack of attachment to the current ways.

And that's perhaps the biggest "natural resource" an AI has: the lack of status quo bias.