As a landlord for 30 years now, I can assure you all costs to the landlord are calculated in rent. If not for the thousands I pay every year into the school system, I would have the ability to charge less for rents which my tenants would love. The only people that really make out are those on Section 8 because the federal government is paying their rent for them which again, includes the cost of the schools. My tenants indirectly pay for the schools just as I do, and none of them have kids in the system either.
But I want to point out something here: If you took a grade of suburban children all doing very well in their studies, and put them in one of your Detroit schools, they will continue to get excellent grades. Now at the same time, you take that grade of Detroit kids and put them in the suburban school the other class came from, they will continue to fail in their studies, and most likely ruin that school as well.
So what this experiment would tell us is that money does not equate academic success. This is also evident by world statistics. The US spends more on primary education than any other industrialized country in the world, but we only have mediocre results to show for it.
So the focus should be shifting away from money and being steered towards figuring out ways to get the parents more involved. That's the real difference between your Bloomfield and Detroit schools. Newer lockers, nicer floors, bigger gyms, doesn't help any child in academic achievement.