Is there any chance a Digital Deluxe Edition Upgrade could be sold? I received this game through a Humble Bundle only to realize I'm missing out on all the content... I'd really love to get the comic and skin but as of now I'm unable to.

Seconded.
I've been interested in the game since well before launch and was thrilled to see the bundle, but having to shell out another $20ish for the full package is disappointing.

Oh, hey, they actually did it!

Looks like they did, I managed to nab it in time thanks to your reply... but I checked the store just now and it looks like the upgrade is gone?

It is not.

Did you try searching for it directly? The base game's store page weirdly doesn't have a DLC tab.

Oh hey, thanks for replying! For whatever reason you DO have to search for it directly, haha. I knew I bought it... whew. Remind me not to search GOG at 3am!