Very few things apply always. Obviously money doesn't, but money is not your garden-variety competitive market like carrots or coal. The only legal suppliers of money are the nation-states that issue it. If you tried to print "money" yourself, it'd most likely be worthless because either nobody would use it (ok, maybe some cryptocurrencies excepted, but for reasons that have more to do with anonymity and a desire to stash illicit savings with a potentially lower probability of forfeiture than anything else), or you'd get in trouble for counterfeiting.