My state collects the property taxes for the school districts, and then budgets that money on a per-student basis to the enrolled schools and districts. School districts are political subdivisions of the state in this case. They are able to raise bonds if the populace in their boundaries passes them, but the bulk of their funding is derived from the state.
Also in my state, the poorest schools are usually the those with the least experienced teachers. Teachers make effort to get out of the poor schools and into the wealthy ones and it's seen as a career path improvement. The wealthy schools do not require as much off-hours involvement and the teachers are under far less stress than at the poor schools, as they have less disciplinary issues to deal with. They're almost assured of being a, "meets expectations," or, "exceeds expectations," teacher at those schools too, without effort.
That's why I want to tie teacher salaries, in part, to the difficulty of the campus. Teachers start out in easy schools, the wealthy schools, but eventually reach a pay ceiling if they remain there. Start them out easy, then move to a campus with say, 40% free and reduced lunch. Increase the pay ceiling, so teachers can earn more in that harder environment. Eventually move them to a school with 80% free and reduced lunch, and make the upper limit on pay even higher. In any event, to get the higher pay, the teacher needs to demonstrate performance in these environments. If they can't demonstrate that then they either don't advance or they get to try a different school in the same tier, and if they still can't perform then either they drop back to the previous tier or they really ought to consider other changes to their career.
I don't want to sound harsh, but at the same time if I don't perform then I don't get to move up in the organization, and if I really underperform then I cannot expect to retain my job, regardless of how much education or training I've undergone. I don't think that it's unreasonable to expect the same from everyone else. I'm not even saying that the metrics used to measure teachers should apply through the course of a year only, but if a teacher's students consistently underperform year after year then something needs to change. That individual teacher might be teaching the wrong grade, or be teaching the wrong subject, or not relate well to the student demographics at a given campus, but if changes or further training still don't rectify the situation then it's not fair to the students to continue subjecting them to that teacher.