What Quicksilver wrote...
Easy stuff: one can peruse and buy from the For Sale Forum until their eyeballs and CC go bad from overuse, without being a Premo member.
To be able to Post Stuff for Sale, one has to be, and should be a supporting poster, supporting the site.
I follow several boards of different subjects and I can't think of one that has a free For Sale section, where anyone could sign up and start selling stuff, without some kind of paid additional membership support.
GL, mD