" It seems strange to pass laws that say those individuals aren't allowed to sell to people that are willing to pay more money."

The sales of every good and service are regulated.

Capital transfers are regulated.

Taxes are based on different kinds of economic activity.

It's not even remotely strange that non-citizens should get a different tax treatment or whatever for sizeable personal assets.

I'm surprised that people are even allowed to do it in the first place.

I have no expectations that I can just 'go to China or Geramny and buy some houses'.