No, you are wrong. Obsidian may have been smaller but you are forgetting that LucasArts took a substantial cut of profits and BioWare had to be paid to use their game engine.
I don't get it. How does Obsidian have the resources and manpower to make all these games? They're an independent developer for one. None of their game have been very successful commercially. Their most recent game completely bombed both critically and commercially. Wouldn't they be better off concentrating on one game at a time?