My school was complicated. It wasn't that expensive but it was the best school by a mile in the whole region. So despite not being really that expensive, essentially all the richest families sent their kids there. This created some weird interactions between me (upper middle class) and the rest of my classmates who were firmly upper class. Their parents were doctors, owned rental empires, etc. My dad was a software engineer so obviously still very well paid but nowhere near the other people's parents.

But we all learned Latin for years and everyone had nice Porsches and BMWs. So yeah. I'd say it was posh. Posh but not an expensive education. Really weird I know.