It's a false equivalency to simply say that homeschooling is cheaper because the subsidy per homeschooled child is less that the per-student allotment in public schools. Homeschooled children must have a home to be taught in, which is a cost, and the unpaid labor of the parent educating the child also has value. My opinions on homeschooling aside, it's not useful to draw comparisons between these numbers. Not every child can be homeschooled.