Perhaps I'm biased because my father is a real estate broker and I've heard his stories, but there is a (probably overpaid) profession of people whose only job is to sit down together and dicker over how much commercial real estate should actually sell for. It isn't a T-bill, where you can just ask the computer, or a stock, where you can just look at the transaction for a fungible unit which sold 5 seconds ago, or even a pork belly, which for an agreed upon quality of delicious piggy goodness can be treated as "implements IPorkBelly" and sold quite easily. (Hiring questions: what methods does IPorkBelly offer...)