The cornerstone of Buffet’s investment philiosphy: Never count on making a good sale. Have a purchase price be so attractive that a mediocre sale gives good results.
Book value is equal to that capital that have gone into a business, plus whatever profits been retained. An investoris concerned with how much can be taken out in the future; that is what determines the company’s worth or intrinsic value as Buffet would call it. Book value is blind to intangibles like brand and so there are opportunities to take aadvantage of the gap between the discepency of the book value and the instrinsic value.
Also read Benjamin Graham, Charlie Munger, & Philip Fisher.