Once the home of the titans of finance Lehman Brothers’ honcho Philip Lehman, a noted American investment banker and major art collector, the historical Beaux-Arts limestone mansion erected back in 1899 by architect John H. Duncan, which is now being used as a state-of-the-art office ideal for live-work arrangement, is now being listed for $49.9 million. Interestingly, the listing-price of this home-turned-office has been dropped by almost 25%, from whopping $65 million to $49.9 million, but it’s still the world’s most expensive office space, costing over $3,000 per square feet, a price which is far higher than the per-square-foot record for Manhattan office spaces. Originally, the house was bought by an investment group for $13 million back in year 2005, and did extensive renovation, expansion and restoration of the space into museum-like offices.