In Ontario, Canada, the public spent $23.6B on education in the 2013-2014 fiscal year. That's total cost, including salaries and building maintenance and supplies and everything else that goes into running an education system. That works out to $11.7k per student per year based on 2,015,411 students in the 2013-2014 school year.

That's similar to what you'd pay in private school tuition, and that's with all the bureaucracy and unions and teacher's salaries (teachers here top out at around $100k salary) and all the other things people complain about as reasons public schooling is a waste of money. It's not; it's about the same cost as private schooling.

But with public funding, a good education is available to everyone, and the public has more direct oversight of the curricula and of standards. As a result, Canada scores well in international school rankings, similar to the best European countries -- which are also, almost universally, funded publically (https://en.wikipedia.org/wiki/PISA_2012#Results).