Both my kids are over 18. The big costs start near or after 18. I learned a ton over the years. Some random thoughts.
Our town's schools held "College Financial Planning" seminars. I first started attending very early, when my older son was 8. We saved a lot to pay for any college, with a marketable major for both. How much did we save for college? $1M. How much was spent? Not yet complete, but close. Older son $300k and he has a great job as a structural engineer and makes good money. Son #2 was not a college fit. Crashed and burned through 1 year of community college. He's now in a welding course that was only $16,400.
Private schools: Our town has a middle school commonly called "the Black Hole". Elementary and high had better reputation. Older son went to private religious school for 3 years. Guess what? Private schools are not universally better than public. He entered high school grade 9. At that point, he could type 120 words per minute, had great writing skills and his math was a year behind, even though it is his strong suit because the private school didn't believe in higher level math. Younger son went to public middle and he honestly would have been better in that private.
Learning problems: Younger son had learning issues. Town IEP committee concluded that indeed, he needed an outside school that could specialize in his needs. Public school head of department changed. Next meeting, they all denied saying he was appropriate for outside school and proposed internal program meant for head injury students (football, mainly). Lawyer costs ensued and after 2 years, settlement covered transport for about half a year going forward and money in the next fiscal year. NDA prevents more info. I'll just say that you can't know ahead of time if your kid will have a learning disability.
Boys and car costs: Expect when your boys get their license, insurance will more than triple. Then they'll total a car, so perhaps limit them to a cheap car. Both our sons managed to do this.
Yes, our kids did T ball and soccer and lacrosse and karate and music lessons and day care and sorry....they're all bush league costs. If you look at day care costs and think they're high, don't have kids. My wife left work after the second one and that cost us tons of money. Ended up putting both kids in part time pre-school. Initially, I thought with her commute being about 12k miles a year that we'd save a ton on car costs. Wrong. She drove 18k miles a year. Where? All back and fourth, back and fourth. Going back to work (nurse) took 5 years of entry level jobs and wages because hospitals won't even interview a nurse besides a recent grad if they don't have at least a year of recent clinical experience. So stay at home can mean going to zero wage and then going to entry level again. And yes, she had to do the new nurse thing with night shifts, weekends and every other major holiday.
Kids are not babies forever, which is what a lot of couples assume. They will hate you when they're teenagers. They'll be morons in their teens. You will be used to police coming to the house, sometimes because you called them.
