What country are you in?
US version certainly exists. I have it on a couple demo discs. Curious, none on US ebay right now... BUT we're talking about PC games. The market for PC games is such that it is difficult to determine value on certain items. Things that are insanely rare can have no known value because you can have a low demand or unknown demand on an item. Rarity doesn't mean anything in the PC Game collector's market like it does for console games because the amount of collectors is very low in comparison.
I have many items in my PC Games/software (even hardware) collection that appear to be rare, but there is no real market for them so they have unknown demand or unknown value.
The best example I could think of off the top of my head is the registered version of Notyet:
https://vgcollect.com/item/123306Which to my knowledge, the only images online (or indexed by Google) of this release is the one on that item entry and the picture I put of all three on twitter.
https://twitter.com/Tripredacus/status/854709245006278657PC Game collecting right now is generally ruled by big box releases of AAA titles, and modern Collector's Editions. Everything else falls into the unknown quantity category.