Fanatical (formerly Bundle Stars) offers Steam downloads of Baldur's Gate: The Complete Saga for Windows / Mac / Linux for $10.79. That's the lowest price we could find by $72. It includes Baldur's Gate: Enhanced Edition, Baldur's Gate: Siege of Dragonspear, Baldur's Gate II: Enhanced Edition, Baldur's Gate: Faces of Good and Evil, and three soundtracks.