Neither of those (ticket scalping or housing) represent a free market, at least not in the US.
Governments protect producers of music, plays, and other live content with copyright, which creates artificial scarcity (no one else can create a performance of the work without the permission of the creators/producers.
Governments also limit the amount of housing that can be built in order to keep housing more scare and keep prices high.
In a truly free market, anyone could create performances of popular works or build houses anywhere and there would be less scarcity.
@Pat no disagreement from me here!
people in that thread are argueing for more government regulation when government sticking it's fingers into the market is likely the cause of the problem.