It depends when you are going to be arriving in Paris. The Air France Shuttles end by midnight -- if you are on one of those red eyes you will be out of look. The last train from Roissypole leaves around 12:15 to 12:20 I think. I have been lucky to get one around 1:00 AM, but that is rare. Also the regular metro will not be operating then so connections will be a mess. The taxi ride is about 250 - 300 French Francs. You are getting about 5.50 / $1 THESE days at AMEX. When are you going to be there? Otherwise you can call a shuttle company for about half the price. I will be in town from 30 December - 4 January then to the south of France for skiing. If you are around then I would be happy to invite to our hotel (Le Grand Hotel) for a drink at the bar.

Best,

Phillippe