Hi!
Each bundle is a product itself with different theme, and they're also a discount themselves, so they can't be discounted further cuz the price is already reduced significantly. Beginner bundle is for plugins from 2025, and Must-Have bundle is a bundle that contains top quality plugins of 2025, 2026 and more plugins will be put in there in the future.
So, if you've already bought Beginner bundle and still hesitate on getting this one, you can get the plugins you want separately.