Ten years ago in France, it was around 279€ and since my familly was in the lowest quintile, it was covered by the state. But i've hear that the true cost was in fact 3.8K€ per student, up to 7K per student if you count lodging. Or around 10K$. For "Elite" schools the upfront cost is between 7K and 15K, and you can add 2K for the true cost (paid in taxes, VAT or income) and 3k for lodging. I say elite but the best school in France for math is actually a public university (ranked 5th in the world or around that), and you can get this for almost free if your parents are poor.