So, let's shut down the public school system, and only those whose parents can afford to pay for a public education can go to school, then, we'll just have to pay for the costs related to the unsuing crime wave created by millions of kids with nothing to do all day, and no future, because they have parents who can't afford private education.
BTW...you don't believe that making sure that a basic education is available for all citizens is paying for the defense of the nation?
You get your state education system and others get their home/private school system.
Lots of stats show private education (religious or otherwise) to be superior as based on test scores.