Here in Brazil widespread scalping like mentioned in the OP is very much illegal. Vou falar português porque eu nem saberia como traduzir isso, mas ó o que diz a lei de crimes contra a economia popular:
Art. 2º. São crimes desta natureza:
VIII - celebrar ajuste para impor determinado preço de revenda ou exigir do comprador que não compre de outro vendedor;
IX - obter ou tentar obter ganhos ilícitos em detrimento do povo ou de número indeterminado de pessoas mediante especulações ou processos fraudulentos ("bola de neve", "cadeias", "pichardismo" e quaisquer outros equivalentes).
Isso sem falar que o código civil veda explicitamente o enriquecimento ilícito. É que a gente toma no cu de outras formas.
That is the law most judges uses for "cambismo" but it is not a specific law and it is not clear enough... so depends of the judge interpletation.
Due that issue with the law vs "cambismo" it was created a new law in the "Estatudo do Torcedor":
“Art. 41-F. Vender ingressos de evento esportivo, por preço superior ao estampado no bilhete: Pena - reclusão de 1 (um) a 2 (dois) anos e multa.”
But again it only cover Sports events.
Plus there is another law Lei 1521 that says you need to take in accounts additional costs line logistics/locomotion, food, etc... that allow you to add these costs to the ticket (or product being sold).... in that case the ticket/product prices will be way higher than the actual market prices.
Most judges add that law to the process when dealing with "cambistas".... "cambista" had to travel to the place to sell these tickets plus he had to eat/drink, etc.... all these costs makes his ticket higher and so not being illegal.
So Brasil doesn't have a clear law for that.
We still get fucked this way even when the thing is still wrtten by law by people who love to find loopholes in those laws. On the grey market here some scalpers are selling the PS5 at 3x the MSRP price.
It is because that law is not really specific for scalpers... it is only being used in some cases.
There is no law for that in Brasil yet... more close is the "Estatuto do Torcedor" but it is specific to tickets in sport events only and even so it can be used other high tier level laws that allow the scalper to increase the price of the ticket.