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 García 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.