Swiss offer millionaires a haven away from the poor. See my 2004 LRC post Immigration Idea:
How about this compromise: we remove all barriers to immigration except one: we charge a fee. I propose we charge somewhere between $1 million and $10 million per family. That way you guarantee you get fairly decent (non-criminal, educated, successful, civil, etc.) quality immigrants.
If, say, 100,000 families (about 400,000 people, say) immigrate per year and pay $1 million each, that’s $100 billion per year.
which was roundly excoriated at Not-Reason.