In theory, the westerners would just be sending their money to desperately poor people.

I'm not an economist, and but I think you could model that as a kind of demand. And I don't think I stipulated to there being a transfer of wealth.

Unless you believe in objective morality, then a policy of utilitarianism, pure selfishness, or pure altruism all may be instrumentally rational, depending on your terminal values.

For me, the interesting question is how one goes about choosing "terminal values." I refuse to believe that it is arbitrary or that all paths are of equal validity. I will contend without hesitation that John Stuart Mill was a better mind, a better rationalist, and a better man than Anton LaVey. My own thinking on these lines leads me to the conclusion of an "objective" morality, that is to say one with expressible boundaries and one that can be applied consistently to different agents. How do you choose your terminal values?