I'm calling bullshit. First off, there aren't even 70 million true psn users. You have people who have multiple accounts, etc. I'd wager there's probably about 20-30 million unique users that have a psn account.
So at $318 per user, you are already down to 9.54 billion for the top.
Secondly, what exactly costs $318 per account?
Money can't buy happiness. Just video games, which make me happy.