Flying (EasyJet) is 255.72 € for all 3 of us, train (Thello) 472.80 €. Plane is cheaper but also need to add on another hotel night in Paris since we would be sleeping on the train but it would still be cheaper and faster to fly. We would have to deal with the airport which will add some additional time and I have never flown over there so I'm not sure how much time is needed prior to the flight and after arriving.
I'm thinking it would be best to stick with the plane but any reason I would want to consider the train?