how much is Gothic 1 worth?

The only way to get it is with the Gothic Universe pack, so 20 dollars.

Probably 19,99, as it's only available on packs.

EDIT: I would even say that you can't gift it alone, since it is only on packs, and Steam Packs can't be gifted separately.

You don't give away Gothic 1 you play Gothic 1.

how'd you get a single copy? been looking to buy one without the rest of the games

3$

Priceless :)

As stated above (or below for SGP users), it will probably give the same amount as the Gothic Universe bundle, since it can no longer be obtained separately.

The only way to be sure is to create a private giveaway, set it to the minimum time (1h) and let it end (don't delete it, or it will count against your "currently running" giveaways!) and see what price tag it gets and how many point someone would need to enter.