>If you're a Russian with enough cash to spare to buy a central London property just as an investment asset, the taxes have to be in triple-digit million ranges to become noteworthy.

Higher taxes don't just mean higher taxes for the Russian, they also reduce the value of his property as an investment.

>Expensive, multi-million-dollar apartments are not affordable by working-class people.

Hence the use of the word "space", not "apartment".