PraetorianWolfie: Full Disclosure: I am a developer with the ScummVM team and have been working on the ScummVM Blade Runner engine (still am, and the Restored Content mode is still considered WIP and actively worked on).
So, the explanation for the two separately sold editions is due to what happened historically with respect to the distribution of this title on GOG -- and other digital distribution platforms.
Originally, since about December 2019, GOG was offering the classic version, powered by ScummVM, with quite a few addons (manuals in several languages, English booklet, concept art book). This release was getting more than favorable reviews averaging on 4.7 iirc.
In summer of 2022, the Enhanced Edition was released, at which point GOG replaced the original release's store page with the new Edition. On GOG the Enhanced Edition did come bundled with the ScummVM powered classic one too at release time and if, you previously owned the classic one, you'd get a 50% discount on the purchase of the EE. (On Steam it did not come bundled with the ScummVM version at release time*, and it is also (still) missing all the extra addons. On consoles it never got the ScummVM version bundled).
Unfortunately the Enhanced Edition, as released, had quite a few issues and as a result it was reviewing very poorly both in gaming sites and players community. There was also some debacle about properly crediting the ScummVM team & community contributors for the subtitles and, from our side (ScummVM developers of the Blade Runner engine), a certain regret that the old original store page with the good reviews was gone and now the game, in which we poured years of dedicated effort in to "resurrect" and improve in every way, was being buried in bad reviews.
So, long story short, GOG restored the store page for the original game only with the original reviews for it, and allowed customers the choice to purchase just that one (and review just that one), despite the fact that the Enhanced Edition also bundled the ScummVM version.
*. It should be noted, that a few weeks after the EE release, the Steam version also got the ScummVM version bundled (with a newer version of ScummVM, which was 2.5.1 -- the official stable at the time).
Also, a few months later the EE got updated (both on GOG and Steam) with significant fixes and improvements, including an option to toggle between enhanced graphics and classic ones while playing the game.
And, just to clarify, the ScummVM team does not get any money from the purchase of either version sold. We used to have an affiliation program with GOG (only), so purchases, only if using a referral url, would contribute an amount to the team, but that program was discontinued more than half a year ago now.
Thank you for the explanation... And thnak you for your hard work. I still wish the original game was discounted at a similar % as the new one, because it doesn't make sense for buyers that don't know the story behind it.