Financially the cost? I pay about 6,000 a month in daycare. 2k a month in healthcare expenses.
Then community wise. Every time I've gone to take them to the movies, or to a restaurant or hell now even the grocery store I always get shafted. Everything is so overstimulated and kids get in the way to strangers trying to ignore reality with their phones. So when one of my kids throws a tantrum everyone's looks and disdain doesn't help. It's a part of growing up that I think most young adults don't realize.
Then for your career it's the most destablizing thing there is. Everyone around me who doesn't have kids the sky is the limit. Midnight PR's and no problem handling oncall. I missed a pagerduty alert when I was careflly bottle feeding my 8 month old who caught pertussis from some idiot who thought they were above that. I had no choice in getting out of pagerduty because 'it's only fair'
Don't get me start on dog/cat people who equate their struggles to mine... or people who have no idea how hard life is already for a kid who is disabled.
Having a family sucks hard sometimes. But I wouldn't change my past for the world. They are my everything. The advantages of having kids are lost on most but I'll let others provide input if they feel like it.