It takes about 45 minutes to get from downtown Paris to CDG or Orly airport though, and half an hour to get from the airport in Marseille to the city center, so

It takes about 45 minutes to get from downtown Paris to CDG or Orly airport though, and half an hour to get from the airport in Marseille to the city center, so by the time you've figured in getting to the airport 1.5 hours before your flight, the total trip time is more like 4 hours. For comparison, the fastest train takes 3:15.