Alen, are you sure those players' wages in Italy are presented after tax, where the tax is paid by the club? I thought so too, but some members on other forum argued it's rather before tax and players pay it, so NET they earn less than their contract says.
And BTW, the highest tax stake in Italy is 43% not 50%, so it would be about 14m before tax in Ronaldinho's case to be paid by Milan, if he receives 8m after tax. And if the club pays that tax of course, which I am not sure.