That’s a solved problem. The solution is called QALYS. Richer or poorer countries can set the total budget differently and then QALYS tells you how to spend it.
I don't know why anyone thinks it is acceptable for human lives to be considered more or less valuable depending on which arbitrary geographical division they were born within. Why don't we just murder and eat each other then? That is how barbaric we are.
What exactly do you mean by the word "acceptable" here? "Finding something acceptable" can describe an incredibly wide range of behaviors, from "not starting a violent revolt over it but still hating it" to "endorsing the thing as being good actually".
Now you opened up the balance of cost and effectiveness. Therein lies the nest of vipers.