When I arrive at Orly airport terminal 1 I will have 17 hr. until my next flight. I arrive at 3pm on thursday and leave next morning at 8:30am. I want to go into the city for a few hours then come back to the airport before closing that evening and stay overnight there until my flight the next morning. What is my best/cheapest option as far as public transportation and tickets/day passes? I can't find clear guidance. I am thinking of taking the Orlyval to the Antony station then transferring to RER B. I then saw that taking the Orlybus is cheaper. Still not sure which tickets/passes to buy and where. Any help would be much appreciated!
Paris Day tickets such as Ticket Mobilis, 1-4 zone at 12.40€ is likely your cheapest/easiest option to cover your travels from Orly to Paris, around in Paris, and back, but beware, you need to complete your journey back to Orly by midnight using any day ticket as they all expire at midnight. Also, the only ticket that covers OrlyVal is Paris Visite, but that is also the most expensive ticket (25.25€).