I was thinking the same thing..Why?? You changed nothing but graphics...But for those who have not played it then it is totally worth it.
I will say that since there is nothig really out on either system (less on PS4) this will sell really well the first week or so 1st off to all the super fans and then the people who never got it on the older consoles.
But if you can wait out a week or so after release I would bet you could get it for alot cheaper.
Heck I have gotten 4 Xbox one games and 3 Ps4 games and I didn't even get my systems yet. But I have gotten them sooo cheap I had to grab them. I just got Dead Rising 3 for $24 at Best Buy (brand new) and got Skylanders Swapforce new for PS4 (Amazon) for 35 bucks in the last 2 days. You WILL find bargains.
I know it may sound crazy I got the games first, but I get every system that comes out so no worries on that end...Just gives me a bigger backlog.