The answer is that both of this 'parents' should do right by their child. If they both focussed on this rather than how much can I get vs how little can I pay then this dispute would not even be in the public arena. If you have a child the principle should surely be that you would want that child to have as good a life as you can provide for.

Following on from this logic dictates that if you want your child to have a good life (materially) then whoever he/she lives with by default will also need to be living a good life materially. You cannot seperate the lives of children from their primary carers.

Sounds like both parties are more concerned about their own selves then the child. The needs of our children should not be used as a weapon or bait in personal battles or grievances. Unfortunately all too often this is what we do as so called caring mothers and fathers.