I dont think its scam proof. But i remember buying for the first time. And it was small transactions I was paying first and slowly you build yourself up. I use this board all the time and I buy from new sellers all the time. I buy with caution, I pay after I receive the confrimation... And i don't buy big from a new seller.
Using common sense, and clicking on the user profile to see their posts works for me...
Not foul proof, but I've done dozen if not hundreds of transactions and bh they all went well.