[TomMckenny]

That's arbitrage.

Capitalism is where the gatekeepers on what can be produced and by whom, control through (typically hereditary) wealth and then use that position to capture the majority of and wealth produced (or wealth harvested in the case of unproductive business such as rent seeking). Dishonesty is not a necessary part but certainly occurs in any market where it is favored.

Incidentally, notions of supply and demand are part of a free market which does not necessarily have to be run by capital.