Once I met an espousing comedian who was also a communist. He wanted to have a one world government, not joking, true story.
Quotes from the Communist Party Manifesto by Marx & Engels, Chapter 2:
"the theory of Communists may be summed up in the single sentence: Abolition of private property."
"In one word, you reproach us with intending to do away with private property. Precisely so; that is just what we intend."
It's much more productive talking to anarchists.
You can refer them back to Kropotkin, whose issue with money was the fact it relied on a central issuer which in turn gives rise to a state.
Many anarchists have adopted this view so fully, they tend to dismiss all discussion of money and carry the axiom "we must therefore find ways to have society without money".
So they're easier to win round as you bring them back to their own first principles -- the lightbulb goes on as they see that bitcoin is a form of money the great anarchist thinkers weren't able to conceive of and therefore a world they want is more possible than before.