If you are looking for a good deal, a PS4 is your best option, I saw one with horizon ratchet and clank and the last of us the other day.
That being said, my PS4 is getting dust now thanks to the Switch, but that is due to the fact that I've played most of the games I wanted on it for now.
If you are looking for different experiences, you should look into what the two system have to offer, the PS4 has been around for a long time so there are many great games at good prices, the Switch games are full price.
Now, the defining factor(for me at least) would be portability. I have a Vita and remote play is awesome, and IF(and that id a ridiculous if, but one that really make or break a game in remote play) the would let you map the controllers, I would have to vote for PS4, but since you can't do that(and for some reason they choose the worst layup for each game) I definitely say Switch.