This is why you have a CLASSIFIEDS MOD, who's ONLY JOB is the classifieds, someone with CRAP POST HOE posts (ditto, cool, ect) just to get a count finds there count never seem to go anywhere, get banned, can't post adds, ect., The FOR SALE ADDS are FOR active members, sorta a PERK for SS members, not the other way around, IF someone is here JUST TO SELL, SS does NOT need them, (unless a PAYING vendor), thay can go and sell there stuff somewhere else.
AS far as "WHY CAN'T I POST A F/S ADD" , thay are on site reading the post, so thay CAN NOT say thay COULD NOT read the rules, I would give ANYONE a day or 2 off for a why can't I post, and tell them "WHILE OFF PLEASE READ THE RULES YOU AGREED TO", no matter how much FIX is done for the site, you CAN NOT FIX DUMB