A team of scientists in Spain have calculated that Real Madrid will have to pay around €55m if they want to prise Kaká away from AC Milan this summer.
A research group at the University of Navarra have developed a method to estimate the price of football players and have set the bar high for the Brazilian superstar.
While Madrid could land their man for €55m, the boffins at the Faculty of Economics and Commerce believe that Chelsea would have to stump up €3m more.
Francesc Pujol, who leads the team in Navarra, and Pedro GarcÃa del Barrio, a professor at the International University of Catalunya linked the price tag to the amount of media coverage an individual received.
For every one per cent rise in media coverage, Kaká's value rises by half a per cent, while other factors, such as age nationality and the buying club are all weighed in.
Along with ability, the price of a footballer will rise because the club that wants to purchase is willing to pay more if they recognise that their target will benefit them commerically.
While many believe that most players are sold because they are no longer useful to their team, the scientists think that it all comes down to how much he is worth off the field.
With each year that passes, a player's value goes down, while the figure is also affected by nationality too.
South American players already in Europe are often under-valued, according to the report, while those of African origin are not.
Whatever price the professors and their teams believe Kaká is worth off the field, Madrid still have the difficult job of persuading AC Milan if his value when he is actually playing.