A woman should never make a man pay child support for a child he wanted to abort. He should have to pay the equivalent for what an abortion would cost, and sign away any parental rights.
A woman should never expect more in child support than the straight cost of raising a child in the region in which she lives. For instance, if you live in Chicago and it costs $1000 a month to feed, clothe, house and school your child on average, then the man should pay $500 a month. It should not be based on what he makes, and it should not be based on whether or not she wants to raise the child in an affluent neighborhood or spend stupid amounts on clothes and food.
If the man wants to have the child, and the woman wants to abort, she should have to pay for the abortion herself and pay pain and suffering to the man.
If the man wants to raise the child, and she wants to give it up for adoption, he can pay all the bills and she can sign away her parental rights to him.
If the woman wants to put it up for adoption and the man wants to abort, he should still pay what it would have cost for the abortion, plus he should sign the adoption papers relinquishing his rights. I could go on and on.
But, there also must be a registry of sorts so that people who have multiple problems (i.e. multiple abortions, multiple children) are treated and possibly held more accountable for their actions on both sides. That is to prevent men from knocking up every woman they meet and demanding abortions to skate out, and women can't keep having children to support themselves on other peoples money.