From what I found, you really need to have a range of Economic textbooks for a variety of purposes.
For example, I used the Creative Economics textbook by Ian Moore prior to classroom learning and immediately afterwards. The book is fantastic for general, surface-level understanding and I would not have performed very well without it.
However, it is not a great textbook for taking notes or deeper, more intricate and nuanced understanding. For that Tim Riley's textbook is brilliant. Dovetailed with my class notes, his textbook was essential in building my core notes and understanding the Economics course more generally.
I also used Tim Riley's and Ian Moore's workbooks and Ian Moore's Creative Economics Study Guide. I found them to be particularly helpful as the often contain really useful tips which teachers do not have enough time to cover, as well as, give you access to a range of questions often not found in past HSC or Trial papers.
By the way, I purchased the Excel book but I would advise against it. Even for general understanding, it is not good enough and some of the things mentioned (like formulae) are simply incorrect.