I confirm.

Yeah, I even own the Digital Deluxe version and the option is still open for me to enter.

Even though I wont be entering, I thank you for sharing Sushisu.

It's OK
don't worry

Deluxe Edition dont include any of the DLCs that you can buy from steam. This is includes:

-Made Man Pack: Free access to in-game downloadable pack that lets players get behind the wheel of two different luxury automobiles modeled after classic cars from the period. In addition, Vito will look the part with two new “made man” suits, including a vintage tux.
-Digital Art Book: Get to know the families of Empire Bay with a photo album-style Digital art book that takes fans through the artistic design process of the game.
-Orchestral Soundtrack: Immerse yourself in Empire Bay’s symphonic masterpiece with the Mafia II score recorded by the Prague FILMHarmonic Orchestra.
-Digital Map of Empire Bay: Get familiar with the neighborhoods and own the streets with the Digital map depicting the 10 square miles of Empire Bay and all the hangout spots.

I guess because it's removed from Steam store, so Steamgifts cannot find the price. Therefore, the site thinks it costs 0$.