Arcania: FoS - Released on Steam
Alistair points out ArcaniA: Fall of Setarrif has been released on Steam (and presumably any other digital vendors):
Fall of Setarrif, an all-new standalone expansion for Arcania: Gothic 4, is now available on Steam!
A new threat casts its shadow over the Southern Isles. A mysterious demon, consumed by hatred, terrifies the population and pools his force against the coastal city of Setarrif. Experience a new, compelling part of the chronicles of Argaan. Face the last challenge - determine your destiny!
Actually, looking at GamersGate, they also have a Gold Edition for $29.99.
Information aboutArcania: FoS