What happens if you buy the base game and then buy the deluxe separately? (Sims4

[camerons829]

I currently have The Sims 4 base game. What happens if I buy The Sims 4 Digital Deluxe separately? Will it upgrade my current version, or add another game in the library? The digital deluxe separate is $9.99 (on sale currently). And the digital deluxe upgrade is $14.99. It would make more sense to buy the digital deluxe  separate . Besides, I like seeing more Games in my library. I want the digital deluxe for the sims 4 soundtrack, since I love it so much. please Let me know what would happen- would it upgrade my current game, or add a new sims 4 again separate with the sims 4 digital deluxe tag at the top?