@SupaPhly part of the reason could be that they are more responsive to FOREX fluctuations than MS or Valve. The other reason is that we are so small for Sony that they can't be bothered to match what happens on the other platforms.
If you have both consoles it allows you to price shop, i've picked up a few games this way.
Welcome to the tropical Alola region! Start your journey with Rowlet, Litten, and Popplio, then seek out the Legendary Pokemon Solgaleo-GX and Lunala-GX to witness the awesome power of a new kind of Pokemon: each Pokemon-GX brings an attack so devastating that you can use only one of them per game! Discover dozens of never-before-seen Pokémon, Alola forms of some familiar favorites, and new ways to battle in the Pokemon TCG: Sun & Moon expansion!