In Los Angeles it costs about $20,000/year per student in K-12.
Assume that each illegal family has four kids. That means each year it costs citizen taxpayers $80,000/year and a total cost of $1,040,000 in 2016 dollars. Think we are ever going to get that back in tax revenue? I don't.
That is just education. add in Section 8, food stamps, WIC, etc and it costs hundreds of thousands per illegal in the USA.