Using black letter outlines in conjunction with the the "Understanding" series is a good approach. Black letter will tell you what needs to be memorized. Understanding will help you to understand what you are memorizing. Then you will have it memorized, and understand it. After this point, the black letter outline format will help you to think about it all in a more organized way. Then, you can confront new hypotheticals (such is the purpose behind Examples & Explanations, among others), if a question pops up that doesn't fit into your new mental framework, you can consult the "Understanding" book (or other hornbook/treatise style aid of your choice) for a more thorough discussion. I think this technique will suit you well when you try to "IRAC"; organized outline structure helps you spot issues, memorization helps you dissertate the rule, a solid understanding of the framework, development, and rationales behind the law will help you with your analysis. The whole combination will help you with confidence and a clear/concise presentation.
As for the other study aids, many serve a separate purpose. For example, High Court saves you time by getting you prepped for class in about 1/5th as long as regular briefing; time that can be used more effectively with other study aids. It is true that you might buy some and not use them, or you might buy some and use them only a little bit. But you do not have to read a study aid cover to cover in order to make it worthwhile.
Anything that saves you time, helps you understand a concept, or makes studying a little less boring, is probably worth it. Don't try to budget the bare minimum on aids, you are going to spend a lot of time studying, give yourself plenty of options on how to spend that time. Sometimes all it takes is a new turn of phrase by a new author to make the lightbulb go off. I promise you, when the year is over you will not curse yourself too much for spending a few dollars on an aid that ultimately was not used, but if on a test you misunderstand a concept unnecessarily, your frugal approach to study aids will haunt you.