Upvote:2
You should be able to buy a prepaid SIM card at any telecom store in France (You'll run into Orange shops all over Paris, although I'm not sure whether you can find one at the airport). They also sell them in many supermarket (bigger ones, like the Carrefour will certainly have them). The information I have, though first-hand, is a bit dated (2+ years), but I've never been asked for an ID.
I mainly use the cards for local calls and I'd say you can call at least 30 local minutes on a card charged with €10.-. However, most operators charge up to €10.- for the card itself, which is non-refundable.