This basketball is so expensive because it has two MJ's signatures on it. Michael Jackson and Michael Jordan used this basketball when shooting the famous cooperative MV Jam. After the shooting, two MJs signed their names on the basketball. The basketball was originally expected to sell for only $600, but in the end an unknown buyer pocketed it at a high price. Experts estimate that if it is called online, it will definitely cost more than $10 million, which will be the most expensive basketball in the world.