Originally Posted by iff

I admit I'm confused here -- a two-day pass? As I understand the question, they're going to be going from Zone 5 to Zone 1 every day for nearly a week.

Wouldn't the best strategy be to get a weekly Carte Orange zones 1-5? (currently €31.50, will be €32 and some cents once the prices change July 1) That would be valid Monday through Sunday, so they would simply need a regular ticket or one-day pass, depending on their needs, for their arrival on Sunday.