You would need a billionaire because actually running things like a libertarian doesn't pay the municipal bills - it's been tried without the billionaire. https://www.texasobserver.org/the-rise-and-fall-of-the-frees...

I was thinking something similar. Though rather than a billionaire, some enterprising libertarian / anarcho-capitalist folks could move there and push the city further in that direction by simply using legitimate democratic processes. Sort of like a smaller-scale version of the Free State Project in New Hampshire. Though maybe a billionaire could provide some seed funding to induce the initial migration.