@Julia ********
Bangkok Pattana International school is more like 20,000 US$ a year.
My neighbour in Bangkok, an American, with 2 daughters (9 and 11) does "home schooling". He found some package, from America. It is online, no need for him to stand above their shoulders all day long.
Still, he pays about 3,000 US$ a year for both of them to go to Bangkok Pattana International school for events, sports, arts, drama and other non-teaching activities. He works from home.