It is not necessary to name a price in the APUG classifieds, though it is what most people do, and you're more likely to make a sale on APUG that way at a price that seems fair to you. If someone wanted to conduct an auction in the APUG classifieds (not a link to another auction site) even that would be permitted, as long as it isn't too disruptive.
If you have a complaint about a post, please use the "report post" button, and the moderators will handle it accordingly.