I will arrive Paris at 0600 and would like to take the Roissy bus to Opera, I checked that there is bus running at that time but the tourist information does not open until 7:15am, are there any other place I can buy the return tickets ? machines ? or dierctly from the bus driver ?

When I took the Roissy bus we paid for tickets on the bus. Also, I believe I just read that the fare has increased to ten euro per person. The bus is a very convenient to travel to/from CDG.

clau888, don't worry. If you are arriving at CDG at 0600, by the time you go through customs and pick up your luggage, I'm sure they'll be open.

As I recall, you can buy your tickets on the bus.

Thanks both.

I have read on "Paris By Train" that there are no longer any fare discounts for children on the RoissyBus, effective July 2011; the fare is currently a flat 10€ for all ages. This would seem to be confirmed on the RATP and "Paris Convention & Visitors Bureau" sites. It is rather odd, considering that child discounts (up to 50% off) exist on most forms of public transport in Paris.

You can find a helpful and up-to-date analysis (including schedules and fares) of all the public and private transportation options between Roissy-CDG and Paris at:
http://air-travel.discoverfrance.net/cdg_info.shtml