Think child support is expensive, imagine having to raise the child yourself. I cannot think of a single instance where a man that has custody of the kids receives support from his ex-wife. Add in not only housing, clothing, and food, it's expensive. Now, factor in child care for while you're working. Even sending your kid to public schools is a bit pricey as the schools always pop up with things your kid needs for classes. Daycare? Unless you have a relative or live in girl friend that doesn't mind watching the kids while you earn a living, that's far from cheap.
Decades before my wife divorced me we were separated. It didn't look like we were going to get back together, so I stepped back and took the pragmatic look at it. The kids were the most important thing to me. Were their needs being met? In our case, they were. The kids had a roof over their head, clean clothes, food in their bellies. Fight the child support and allow her to use that against me? No way! Paid it regularly, never fought it one bit. Surprised the hell out of her because I pointed out in court, much to the disgust of both our lawyers, that the kids came first. Ended up getting back together. Had I tried to get the kids later on, I set a good foundation of showing that my concern for them outweighed the anger at her. I made sure that was on record in the court, without mentioning the possibility of my attempting custody down the line if the kids weren't taken care of. Judge never saw anything like it. I actually came close to getting contempt of court because I put my kids well being above that of the judge's. we ended up getting back together later, before the divorce was final, and stayed together until our grandkids were in school (the oldest one had been out of school a couple years, even)