I can't speak for other countries, just ones in Vietnam. Some are very expensive and some not. But a lot of parents put their kids in international schools here at a very young age and those schools are expensive. 2-3k a month for a little kid to go to an International school here. My friend sends both his kids to one and he pays 5k a month. I told him he is wasting his $, they are 5 and 7 years old. Save that $ for when they are older and use it for a University, there is no need to send a little kid to a school like that at that age. But the parents here do it.