I fully agree with that. you can book your tickets on www.voyages-sncf.com and pick up the prepaid tickets at the SNCF counter at CDG rail station any time before your train leaves. (you will need to show thre credit card you used for booking) definitely the best to do. if you take rental car, you need to add toll on highway, very high gas price and so on ... definitely: go by train and rent a car locally at avignon or aix en provence tgv rail station.

if you need any further help with the booking - no problem. just post in this thread