Some European countries have introduced a system, so that very rich people from anywhere in the world can buy either citizenship or permanent residency permits. In this way they have full access to the whole Schengen area. The countries are Malta, Latvia, Portugal, Greece, Spain and Hungary.
Yes – it is true. These matters are fully national competence. Not European. So legally is it ok. But politically and morally? It is certainly a way to undermine the public support of the basic right to free movement. And this is very regrettable!