One of the keys to value investing, as opposed to just buying whatever’s cheap, is looking for details in places that other people aren’t, whether that be an unloved sector or a region in turmoil, and finding the diamonds in the rough. If spinning of businesses with different valuation multiples is part of the standard activist playbook, it stands to reason that big conglomerates may be especially unpopular right now, and according to the recent issue of Value Investor Insight, Graham Holdings Co (NYSE:GHC) is worth taking a look at. Boyar’s sum-of-parts valuation With so many different lines of business under…