Silman's idea and explanation of examining and using a position's imbalances, finding a realistic position, visualizing a desired position and then attempting to see if it can be obtained was worth the book's price.
Did Silman invent this "method?" No, you can find it assumed in other books, but Silman explicitly creates the framework.
Does he explain his method clearly? Yes, I've used his method successfully in my games and in studying other chess books.
Is Silman the last word? No, the many typos, redundancies, omissions, etc., make this a less-than complete book.
Will this book help improve your game? I think it should not only increase your skill level but will also help you to get more out of other "better" books on tactics, strategy, endgames, and so on.
Silman is a must read for all non-Master rated players who want to be Masters.