Paris Airport Taxis – from Paris-Charles de Gaulle Airport – are expensive if you are travelling on your own, but proportionally cheaper for more people.
The advantages of taking a taxi from Paris-Charles de Gaulle Airport into the centre are obvious: you dump your luggage into a taxi at the airport, sit back, relax, and let the driver take you directly to your hotel – and, if you get a chatty driver, you could learn a lot on the way.
The downside is cost: the fare is probably 60€ to 85€. In terms of cost per km, however, the taxi fare from CDG to central Paris is much less expensive than many other European cities.
Also, depending on traffic, the taxi can take longer than
the RER train, and time-wise might be no quicker than the less costly Air
France bus or RoissyBus.
Whether or not to use a taxi will also depend on how close your destination is to an RER Line B train station, Métro station, or airport bus stop: if its close to a station, you might save time—and will certainly save a lot of money—by taking the train and Métro, or an airport bus.
If your destination is a distance from an RER Line B train or Métro station, or from the Air France bus or RoissyBus stops, you may still have to take a taxi in central Paris.
There is much to be said for using a taxi. Sure, it's costly, but it's very direct, and can be quite exciting.