His ex-girlfriend is trying to get more money out of him for child support. He is already tapped out. He feels if he gives her any more money he won't have anything to give his little girl when he has her. He feels that if she gets more money out of him that he will have to give his daughter up and relinquish his parental rights to the mom because he simply can't afford to give her more money and survive. Are there any suggestions out there for my friend who needs advice?

What are you talking about, why do you believe that "giving up rights" means you don't have to pay child support, one has nothing at all to do with the other. Giving up his rights merely means he can not see the child, he can not have any say in the raising of the child,
But he still has to pay all of his obligations, child support, court ordered health insurance and the such. Only if the ex would marry and someone wanted to adopt the child, would the child support stop.

So are you saying his love for his child has a price? That he would rather not see his child to save some money ? I will not go with an opinoin of that, but what he needs is an attorney and have the court set the proper child support due, using the state required formula.

Is there a court order? If not, get one. If so, he can gave it modified and decreased upon the birth of another child.

With respect to vlee answer, that will depend on where you live, in many places the entire amount you pay is based on only the non custodial parent salary. Not the number of additional children but your state may,