"Buffett" is a biography of one of the most important and successful people in the business world. Buffett's life is a story of success of the most impressive kind, not a single lucky hit but a career going in stages mostly (but not always!) from one victory to another. One would be quite irrational to miss an opportunity to take a closer look at what made him the person he is and what made his success so huge.
This book offers a very decent and detailed overview of Buffett's biography. Over 500 pages of nicely presented data from the life of the great investor, some of which you will certainly find rather surprising. I have heard of people paying thousands of dollars to lunch with Buffett (which, apart from being rather funny reveals a less known face of Mr B - the money from the auction went to charity as did most of his private money) so investing a few quid (and a few evenings, it takes time to get through this bulky volume) sounds like a fairly reasonable investment in times when reasonable investmens seem few and far between.