Next to nothing.The cost of someone buying a PS4 to then get a PSVR will be gigantic.The PSVR is clearly targeted for people that already own a PS4 and even then, and thats my opinion, wont sell like hotcakes.
My (locked) thread about how difficulty should be a decision for the developers, not the gamers.
https://gamrconnect.vgchartz.com/thread.php?id=241866&page=1