Hi, myself and a friend are travelling to CDG on Sunday 10th June. We are going to Eurodisney from the airport but plan to go to Val D'Europe for the supermarket and we also will be travelling by RER to return to CDG on the 13th. Would the cheapest option be to purchase a Navigo pass for a week starting Monday and pay for the tickets from CDG to Disney on the Sunday? Or is there a 10 trip carnet that's valid in zone 5?
Your cheapest option would be to buy single use tickets for Sunday when you arrive to get you to Disneyland and from Disneyland to Val d'Europe.
After that if you're planning to use trains to visit Paris during your stay, it would make sense to purchase a week Navigo which will also cover you for CDG Airport on your return on Wednesday 13th of June.
Keep in mind you may purchase the week Navigo at CDG airport on Sunday upon arrival for use from Monday June 11th till 13th. The Navigo week pass simply won't work on your first day (Sunday). This will save you time buying tickets/passes as you can do it all when you arrive at CDG at the train station ticket offices at the airport (which definitely have English speaking staff.)