Been a fan for over 50 years and have all of the books and recordings available when they were originally released (including many, many hours of Radio Free Oz and the "
...Joke Book you mentioned. Behind me, are even VHS tapes of their early work). Drove some people cRaZy in school back then, but most of them would come over to the house just to listen to them again and again. This is just the latest release you can get. I think I have everything they've ever offered on their webpage: t-shirts, bumper stickers, license plate holder, books, various collections, etc - incl. some that aren't even there anymore.
If you consider buying just one thing, then I'd recommend their "
Duke Of Madness Motors" collection! Also, the
...Magic Mushroom book comes with a DVD-ROM too. Check
Bandcamp as well.