Those examples are cheap because you can arbitrarily produce more than you need. As counterexample, consider things which you cannot arbitrarily produce more of — licensed drugs, lottery ticket combinations, shares of a company you’re not already running. In all cases, it is possible to buy enough that you’re excluding other people from buying any. In the case of licensed drugs and similar, this is why monopolies are regulated. In the case of lottery tickets, it’s one of the few “winning” strategies and (Some? All?) places forbid it. In this narrative, energy production is limited at some imprecisely defined level, so more cannot be produced.
