The PS4 was still more expensive than the Switch even with their temporary price cut in 2015. Both consoles have yet to receive a "mass appeal" price - cut, but the fact is, Switch will be more affordable in general than the PS4 is when comparing their lifetimes.
A $199 PS4 would be a whole different animal. Especially in Europe and ROW where Sony has a stranglehold. It would be comfortably up YOY in NA + Japan. Even this late in the generation, I can see 18 - 20 Million FY, if Sony do a $100 price cut in March. Very unlikely though.
Nintendo has no incentive to cut price this year either.
But PS4 is much more powerful than Switch will ever be, at that time was easily most powerful console on market, had 500GB storage and BD support. And like people already stated to you, PS4 had permanent price cut in 2015. to $350 and was selling for $300 in November and December. Switch will more afordible, but Switch will be also always much weaker, it will have less storage, it want have Blu-Ray support...they have different price point but they also have different values, both consoles are and were priced like they should, sales proves that.
Same could be said for Switch, Switch at $199 would be a whole different animal, so I don't point of that comparison.
Switch entering its 3rd year on market this year, only few consoles in history buy that time (after 2 hole years) didnt had price cut, Switch will most likely have price cut to $250 this year.