Cheap PS4 digital copy?

[sethnintendo]

PS3 version is 50 or 60? So if you paid 50 and then another 10 you would have paid at least 60 dollars. You would then sell your PS3 version for 30-50 dollars. 60-50 (max) = 10 dollars spent for PS4 digital. I don't see any money making in this deal but a potential for a cheap digital copy on PS4.