the sense of 5 posts is.... none, better way would be 0.01 or 0.005 btc to get full access.
People would think twice before troliing
I like the idea of a tiny initial fractional charge for posting; plenty of other forums out there have a small one-time fee to keep the trolls and spammers out. It is a bit of a hassle to build up five newbie posts so that I can thank the cudaminer devs and post my rig specs for feedback.