I mean, SR started charging for sellers accounts and that money is gone. I see this a very viable solution. Buyers are going to deposit money anyways. This way, most buyers would be forced to use all their bitcoins before making a new account. It won't solve all issues, but I think its a good first step to thwart reverse scams. Not only do this, but also have a rating system. That way seller number 2 knows what experience seller number 1 had. It just makes it much more difficult for a buyer to scam, but yet it shouldn't hinder buyers to come on board.