Pricing of Black Ops 4 Deluxe Edition

Currently Black Ops 4 Deluxe Edition which contains base game + Black Ops Pass is on sale for 40€.
Base game is 20€.
The Black Ops Pass is not on sale and costs 50€.
Why is the Black Ops Pass not on sale?
I can’t even buy the Deluxe Edition since i already own the base game.
This is extremely stupid.
Please put all dlc on sale too if you put the game on sale or make it possible to upgrade to the deluxe edition.