if you are interested in what philip k dick thought/felt then his personal introduction to this collection of his early short science fiction stories is very interesting and perhaps by itself worth buying the book.
the short sci fi stories are dated and it seems as though they are presented in chronology order as they seem to get more advanced as you go through the book.
they are not his greatest collection of stories but there are a couple of great ones and you can see how he develops through the years.
the war with the fnools is a very very short story and is in the same style as his more crazier psychedelic style stories like the ganymede takeover and the eyes have it, so if you like those 2 then its worth getting for the war with the fnools.
at the moment it seems you cant find this particular book or collection on amazon in the philip k dick book list or it might be called something different – watch out for the book about the single story also called the golden man as that is only for that story and not this collection – but you can at other places like abe books.