Total spending on a annual per pupil basis in a public K-12 school system is 13k USD. https://nces.ed.gov/fastfacts/display.asp?id=66
That averages out to about 300k in a classroom of 23. Money has never been the issue when it comes to the poor performance of the average student. Even if teachers are struggling to get the supplies they need, that seems to me to be a problem of poor budgeting and allocation by the school system.
The school systems with the highest levels of funding tend to be in big cities, and also have the poorest performance rates. Per pupil spending in DC Public Schools exceeds 29k per year and it is one of the lowest performing school systems in the country.