Well.....At $20,000/per year/per kid that adds up darn quick. And...Yes! That **is** what it costs to school a child in a government school.
I agree on your numbers. In my opinon, there’s no way he could be free-from-government assistance in some manner.
Sorry but I smell something wrong with the initial story. The man was permitted to stay in this country for so long, why NOW is he pending deportation? If he has NO CRIMINAL RECORD, is gainfully employed, give him a Green Card and leave him alone. There are numerous such families in the U.S. with similar stories. Something is amiss.