While I can’t speak for FixHepC or the Buyers Club, my take on it is that the Pharma’s Market section is not available for public viewing because the feeling is that those who become forum members are more likely to spend some time reading other sections of the forum as well as thoroughly reading all of this section. As a result they will be in a better position to understand that listing in this section is not necessarily a guarantee of the sources listed and that the situation in this section can change over time as more information becomes available. If this section was open to public viewing that brings the risk that people would only look at this area and may take it as being complete approval of all the sources that get mentioned. As I am sure you are aware, that is not necessarily the case.
And for those who are interested rather than just casual browsers, registration is a straightforward and relatively quick process. 