> There is not much point for anyone to go to the UK to study CS for that amount of money (unless they already live there, but they get their degree for a third or even less of that money)

A lot of people do though. There are lots of international students, many from low and middle income countries. Obviously from high income families.

> It's normal for international student tuition fees to be inflated by many universities, they try to collect some extra revenue based on a perceived extra prestige,

In the UK the government heavily subsidises the fees of British students (basically defined as having lived in the UK for the previous three years, other than on a student visa - there are some other complexities but that is the simple version) whereas overseas fees are the full market rate.

> Similar to charging different prices for tourists than for locals.

Not a thing in the UK.