Leroux: Shadowgate (2014) is 85% off on GOG now and DRM-free. Oh well, so much for the advantage of pre-ordering the Groupees bundle ... :D
I'm pretty sure GOG decided to make the price of the vanilla version below the groupees pre-order price, just to teach us a lesson ;-) I'm unsure if the bonus stuff is really 2,5€ worth for me. I'm not interested in artbooks, soundtracks, avatars and such thing, just gameplay-relevant stuff, but I know the comic and the map can be helpful.
Edit: Ok, decided to go with the vanilla version. It includes also the hint comic, so I miss only the map. If I really want the map someday I can wait for a sale of the DLC-uprade, so everything is cool.