I have a BS degree in computer science from UMass Lowell. I started the family, married, moved into a place of my own, and started an OS kernel developer job just a bit before finishing the degree. At that time, back in 1999, my starting pay of $48,000 ($73,628 in 2019 dollars) was more than my wife's parents made together. You can wait forever trying to get your life into a perfect state for starting a family, or you can just get on with it. Once we had two kids, my wife gave up on that same degree with 75% done.
I currently work for a government contractor, doing low-level software: https://news.ycombinator.com/item?id=20088647
I mostly stick to living in small affordable cities like Melbourne, FL. The area I'm in now is just large enough to have commercial jet flights, 4 each way with Delta and 3 each way with American. Houses have a median price of about $150,000 here. I paid about double that to have a big house (3500 sq ft, 0.39 acre) less than a mile from the beach. I paid it off in 8 years.
Unless you count opportunity cost, there are no child care expenses. My wife does that. The kids are homeschooled, with dual-enrollment providing free AA degrees that have fully transferable credit to state universities. There is a scholarship that should cover the rest, except that we botched the application for the first two kids.
Food is the big expense. We seem to spend over $40,000 per year on it. About half the time we hit the out-of-pocket maximum for health insurance, which is something around $11,000 if I remember right. (skull fracture, major rib cage surgery, more rib cage surgery) After that I don't know, but it might be electricity or home insurance.
My state has no income tax. I don't really pay the federal one, due to the kids.
Maybe the important point is that I just went for it. Sensible career and expense choices help, but the main thing seems to be this: You can wait forever trying to get your life into a perfect state for starting a family, or you can just get on with it.