Cheap travel from Paris
You can use http://kelbillet.com with the cities and date to see different options.
Bus
[edit]Bus is slow, cheap (except last minute), comfortable, quiet, can provide light, fresh air, power outlet, wifi, toilets.
http://flixbus.com
http://ouibus.com
http://eurolines.com
http://megabus.com (for UK)
Car-sharing
[edit]Car-sharing is quicker than bus and slow train, very flexible for time and places to pick up and drop, cheaper than train and sometimes bus, often the best last-minute choice.
Comfort depends on the car, your seat, the number of people ; you can socialize with people or endure silence or driver-chosen music, no wifi, no power outlet.
http://blablacar.com the most famous and successful, includes a 20% website fee, you may need a phone number to book a ride
http://covoiturage-libre.fr
http://idvroom.com
https://eco-voiturage.fr
Train
[edit]TGV is quick (up to 300 km/h) and expensive, you can buy a cheap prem's ticket up to 3 months before. You can even change your mind last minute and resell the ticket.
TER is the slow train, slow and expensive unless you have a discount card.
http://voyages-sncf.com the official website
https://thello.com France-Italy night trains
http://kelbillet.com and http://trocdestrains.com to sell and buy prem's ticket people decided not to use. More demand than offer. Beware of scams.
Plane
[edit]Plane is quick (except for the time lost going to the airport, security checking, some margin), noisy, stressful, limiting in what you can carry.
http://ryanair.com (from Beauvais, 17 € bus or 8 € car-sharing, see Cheap Paris)
http://wizzair.com (from Beauvais ; cabin luggage even smaller than usual)
http://easyjet.com in Europe
http://wowair.com proposes cheap flights to USA by Iceland
http://vueling.com mainly Spain and Italy
http://airfrance.fr France main company, don't expect cheap prices
I can't list all whatever, to find flights: http://google.com/flights http://kayak.com http://skyscanner.com
