Nice points DalBuc. I personally do not believe there is any dollar amount that we can throw at public education that will solve the problem. The problem is, I think 2 fold: 1) Lack of parental involvement.
2) The standardized testing system is bunk.
Parental involvement matters there's no doubt but a lot of the failure is buried in the educational system itself. Parental involvement is what gets a kid from C to B or A but the most basic C level education isn't a matter of parenting. People act like turn of the 20th century parents were deeply involved in education when in fact for most of them educzation was an annoyance that kept their kids from farm duties. Despite that lack of interest that 1880-1910 phase was the greatest expansion of literacy and education in this country. We have a gross failure in the education system to teach fundamental skills in favor of electives and technology. One of the most telling things I've ever seen is that in 1905 high school curciculum in Hugo, Oklahoma (and yes I've leafed through it in their local museum don't ask why) was much more rigorous in core subjects than my education in the 1980's and that 1980's experience is tougher than what we have now. Couple that with the pathetic knowledge and skill level of the average teacher and we have a crushingly obvious scenario for failure in the educational system.
Testing is sub-optimal but here's the flip side. In the Dallas County Community College District, Texas Instruments sponsors a Rising Stars program. This program awards tutition to any graduate from the Dallas ISD with a B or better average. Here's the problem, over half of these "Above Average" students are in developmental classes for both math and reading. Around 10% get dumped into something called the "Success Express" which roughly 5th-6th grade level work. Testing is a bad tool trying to level the playing fields between DISD where they pass out A's and B's like candy on Halloween and school districts that have a tougher set of grading standards.