How many software packages is too much?

I just saw a question at SmartDataCollective about how many data mining packages one needs. He writes,we found out that a particular client is using THREE Data Mining softwares. Not statistical softwares or the base versions, but the complete, very expensive Data Mining softwares – SAS EM, SPSS Clementine and KXEN.I was like, “Wow!!! But do you really need 3 Data Mining softwares???” Our initial