It is unlikely to be the case, that I will be willing to pay more for the ability to violate your rights, than you will be willing to pay to be protected from this ability. It's not impossible, but it's an unlikely situation. But you can imagine counterexamples. (...) Suppose we're in a society, where almost everybody regard heroin addiction is a really horrible thing and therefore would much rather patronise an agency which goes to courts which holds that you can be locked up for using heroin than one that doesn't. Under those circumstances you would get an unlibertarian law coming out from my market for law - you would get a law against the use of heroin. On the other hand, under those circumstances you would get that law coming out of the government produced legal system as well, as we observe that we in fact do get. So the claim I would make is that it's at least unlikely that you would not get a substantially more libertarian outcome from what I just described, than you would get from the political alternative which is what minarchist position ultimately end up with - namely some political mechanism generating legal rules.

David Friedman "A Consequentialist Theory of Anarcho-Capitalism"