Then those many should spend their own money. And not steal from the rest of society.

Maybe they could sing up for say extra 20-50% tax which then get distributed.

Steal from the rest of society? Would you cop yourself on. Governments levy taxes and use that tax money to fund things that they think will benefit society. A la carte funding of the bits you think are worth funding is not a workable proposal. The Irish government funds lots of things I don't agree with but characterising that as theft is ludicrous.

We do, it's called income tax.

I mean 20-50% on top of income tax. Putting your money where your mouth is. That percentage should not be too much for anyone truly passionate and willing to make some sacrifices.

Libertarians will not be satisfied until everybody suffers maximally.

I can't afford a painting. Noone in my neighbour can afford one. Together, we might, and we could put it on a wall in a communal building. Let's call it a museum.