The National Gallery of Art has recently acquired a complete set of Albrecht Dürer’s 16 woodcuts illustrating the Apocalypse for $1.4 million. It is one of only a few surviving specimens of the 1498 edition. The New York Times article states the Swiss dealer August Laube as the seller.
The most famous woodcut of the Apocalipsis cum figuris (“Apocalypse with pictures”,”Die Heimliche Offenbarung Johannes”), which was published at the same time in Latin and in German, are the Four Horsemen, depicted here. For the first time, each of the woodcuts bears the famous AD monogram. Thirteen years later, Dürer produced a second edition, but it is apparently the first edition which causes Museum and Art Gallery directors to invest large sums of their budgets.
This website (in German) gives a fine overview of all 16 woodcuts along with some short commentaries.