Folks
some may want new shiny books to keep as a PPL memory but you can find most Trevor Thom books or any other series on ebay going for as little as a pound. Even if they are the older editions, it doesn;t really matter.
Also, if you are interested in the full story, it's good to have the complete book.
But if you only want to pass the test, the confuser will be more than sufficient.
Stuff like Human Performance, R/T... don't really need the book unless you want to read it all for your own interest.
But as far as the test is concerned, the confuser will do the trick !
regards
w.