I have to touch on this. Every time I've pm'ed a mod to get a title changed (for ex: for sale>price drop) or a price change, it's taken no less than 4 days to get a response. Marking threads sold takes a while, too. I understand people get busy, but this has been consistent since the first thing I sold here.
One thing I think should be added to the sales thread tools is the ability to mark threads as solved, which in turn, tags them as sold and close them. That would take a little strain off the mods, and stop people like me who constantly troll sales threads to not get all excited until we realize (after pm'ing) it had been sold 2 days or a week ago.