I have the same question, but think we can answer it by reasoning.
If it could be purchased for $0, only the first stock would cost $0, and the price would then rise, but how would we calculate the price increase for a stock purchased at $0 that is now worth $0.1? So that's not it.
If it were not for sale, why would it be listed?
I think it's the third, and I'd further guess that any bid for the stock will be accepted, thus setting the price.