This quest is not available in game.
Get Augustus' Receipt Book from the inn in Terrordale.
I'm ready for business! What you do want?
Oh wait... I can't open up shop without my receipt book. How am I to keep track of things without my receipt book?
I must have left it in town somewhere. I had a room in the inn... the book must be there.
Bring me my book. Please, bring it to me! Bring me my book and you'll see! I'll set up shop and you'll see that my prices are INSANE!