In my experience, German versions do not typically add value to games that were available in the US, regardless if they share a name.

Now, some collectors put a personal premium on games. For example, Alligators are rare in the US and a collector may place a slightly higher value on the game due to its rarity. But to a casual collector, Bally Alligators and Gators are the same game. So a change in title is not enough to entice them to spend more for one version or the other.

There are always exceptions, but for the most part, the German version is worth the same amount as the US version.

At least, in my experience.

Marcus