We will miss Portfolio's napkin math sessions when the magazine eventually closes. Last month, they calculated the net worth of Led Zeppelin's "Stairway to Heaven," supposedly the most profitable song ever recorded, which earned an estimated $572 million. Now, they've moved on to other pop culture fare: Project Runway. Just how much is the fashion reality show franchise worth? Well, The Weinstein Company's new deal with Lifetime pits the show at $150 million over the next five years. But if they were to sell the show? $243.5 million — the insurance policy on Heidi Klum's legs not included.