I actually didn't know that the Forbidden West had the DLC on cart, which I think is the first Sony owned game that did that. BG3 doesn't have DLC, in this sense though does it? Just free updates? I don't think those are treated as different SKUs in the sense that the DLC is treated.
That’s not how sku’s or DLC’s work. Dlc is ANY downloadable content released after the initial release of a game. This includes anything from bug patches to all new content. They do not need individual sku’s. Sky’s are a retailers personal unique alpha-numeric code used to tracking inventory.
The only things that require sku’s are items that are released for sale. Most patches for example would not need skus because they are not sold. The base cyberpunk game needs a sku, the dlc needs a sku, and the deluxe version needs a sku as they are all separate products.
The deluxe version already needs a unique sku because it came with patches and the free dlc for the base game that came out with PL. That’s the point of deluxe editions that release long after launch. Whether the PL DLC was on disk or paper would not impact the Deluxe edition needing its own sku.
Witcher 3, Disgaea 6, dredge, metro exodus , Horizon zero dawn, horizon forbidden West , dead island 2 ultimate, tiny Tina chaotic edition, disco Elysium a few others that are complete editions on PS5 released as discs after initial release via @doesitplay.org
Anyway, certification pricing appears to be confidential, I'm unable to find numbers and what I can find suggests its negotiated differently per publisher. All platform holders do it, but Xbox got it all on disc and Sony didn't. The Nintendo launch is the first, so it makes sense to bundle it all.