Equality

Rawls' maximin is not strictly an egalitarian position because it seeks to maximize the position of the worst-off members of society, regardless of their position relative to everyone else in that society.  For example, the principle of maximin says that it is better for some people in a society to have 25 of a certain thing and others to have 40 than for everyone to have 20. Everyone having 20 would be the egalitarian ideal, because each member of society has the same amount, but according to maximin, it is better for the worst-off people to have more, even if it is less than other people have.

In the theory of spheres of inequality, unequal distribution of money is okay as long as it is caused by people's ability to make money and it doesn't influence the distribution in other "spheres" like education, politics, or health. Inequality is only bad if it is not justified by a person's ability to make money. For example, it is just fine that a person who makes more money drives a nicer car than someone who makes less, but it would be wrong for the richer person to have more influence in the political process than the poorer person does.

It would be good for GDP if poor, smart kids were helped into better schools because they would then have the education necessary to become more productive adults. This might be inefficient in the short run, but in the long run it would be efficient as long as these children produced more as adults because of their education than the extra cost of helping them into that education.