A free market simply means that individuals are free to conduct consensual transactions with others. In other words, they aren't compelled through violence or the threat thereof, to make or not make transactions that they otherwise would.

Generally speaking, what all other definitions boil down to is Sam and Hanna wanting to make a consensual transaction, and some third party who has nothing to do with said transition interfering "for the greater good" or whatever. Which is nonsense, it's the complete opposite of freedom.