Apart from 2001/02 and mind you that Real already had a stellar team, with the likes of Carlos, Figo, Raul, Hierro, they underachieved in Europe for more than a decade. Juve smashed them on every occasion they met, 2002/03, 2004/05, 2008/09 and recorded better results in the CL.
The point being made here is that Zidane's sale helped Juve to build more competitive side, and the real difference in incomes between the two clubs, who were pretty much side by side even after Zidane's departure, started after calciopolli.