Sotheby’s Imp-Mod Evening Highlights May 7, 2013 by Marion Maneker More from Art Market MonitorBonhams Sitting in Auction Margin ‘Sweet Spot’ So Is It Time to Sell?Who Bought What at Christie'sOld Masters 69; Contemporary 70Cohen's Motives and Other QuestionsFrieze Runs on Used Vegetable OilArt Miami: Day 1 Sales