There are, realtors, say, three reasons why great real estate comes on the market. Death stalks us all — as it has 740 Park this year, where several elderly apartment owners have gone on to less limestoney pastures. But this week, debt and divorce have taken center stage, thanks to hedge hog J. Ezra Merkin‘s misadventures with Bernie Madoff and now, per Page Six, the impending divorce of United Technologies chairman George David, and his “stunning Swedish Countess,” the former Marie Douglas, an illegitimate descendent of Ludwig of Bavaria. The Davids have split up and reconciled before, so maybe they will again, but with pit bull divorce lawyer Bob Cohen in her corner “fighting for the 10,000 square foot penthouse” that was created in 1929 for Vanderbilt heir J. Watson Webb and his bride, the arts patron Electra Havemeyer, it’s likely this divorce will end in tears — and perhaps, a new Manhattan coop sales price record. The floor plan of their fabulous triplex is shown on the end papers of the hardcover edition of 740 Park. It’s worth fighting for.