The For Sale section is an extra service or benefit to members. It is not the core focus of this forum. As mentioned you need to be on this forum at least a month and be active. Spamming your way to 50 posts with a lot of nonsense posts will not go unnoticed either. Those posts would be removed and you might end up being blocked from the forum.
These rules are there for a reason. There were instances were new guys advertise items, and barely with photos or obsolete old photos. Then the buyer came running to the moderators asking for help on a bad transaction. Hopefully within a month of being an active member you will be known a bit, and others can have a feeling of trust in you.
We had these rules in place for years. OK, yes previously the minimum post count was 30 and we did recently moved that up to 50 after issues.