Amen to the childraising point. My wife and I took a total of six months of leave for each of our two kids (mostly her, though I did a 1-1.5 months at the end too). That's a year's salary down the toilet. We're mid-career (i.e. unlikely to see an increase in real income unless we get lucky or change career paths). So that's probably 1.5-2% of our lifetime earnings right there: even before the kids started daycare, and long before they'll go to college.
The love and affection what you gave to ur kids is priceless and much more valuable than the money (1.5-2% earnings)you drained. So, Don't even account it. With out these (spending time with kids taking off etc) how much ever you earn, you are still poor.
He was referring to the first six months of child raising. Therefore, the total cost is definitely higher and may well trump taxes, depending on when your definition of "child raising" stops.
The loss of income for 6 months was 1-2% of his lifetime earnings. I strongly doubt that 6 months of taxes will account for >2% of his lifetime earnings.