I´m planning a trip (in November) to Calafate-Chalten area and would like to visit Torres del Paine too. Any idea of how to get from calafate to Torres del Paine area ??? Bus or just plane ?? Any idea of costs ???
Thanks for the info.

Hola Javier
Desde la terminal de omnibus de Calafate hay omnibus todos los días que te llevan a Torres del Paine, creo que paran en Puerto Natales. Si necesitás información de El Chalten avisame que tengo mucha. Saludos Héctor

There are a couple of buses leaving from Calafate to Puerto Natales every day (4 hours)
Then from Puerto Natales there are 1 to 3 buses per day (depending on the season) from Puerto Natales to Torres del Paine (2 hours).
For the trip from Calafate to PN, if you go in November I think you can book a day ahead, it's enough. To be sure, 2 days before is better.
From PN to TDP, you can book when you arrive for the next.
All buses are in the morning as I recall so it's quite hard to arrive to PN and go directly to TDP.
A good place to sleep in PN is Casa Teresa. Cheap and welcoming.

An important thing to know is that there are 3 stops within the TDP National Park. So depending on what you plan to do (W circuit for example) it is worth checking where to get down, and where to take the bus again when you leave. It could save you some walking...

Feel free to contact me if you need more infos.

Two ways to get there:
First, Bus via Turbio to Natales (5-6 hours, around U$D 20). Night at Natales (U$D 10 plus food, remember not to take anything fresh, cheese, ham, etc. to Chile, they will confiscate it) and then bus to Paine (U$D 15; there is a new road under construction so it might be faster). Inside the park it could be another hour depending were you get down (inside TDP you could only move by bus or “dedo”, it’s to huge for walking).
It might be best for you to go by Cancha Carrera (Arg)/Cerro Castillo (Chile). There are some direct buses (ask at Calafate or Rio Gallegos) or you could take the bus to Rio Turbio, get down at cross road with Ruta 40, hitchhike the 6 Kms to the frontier, and once more bus or hitchhike from there to TDP. This would usually take not more than 6 hours and cost U$D 20.
The only problem I see with your question is that if you need to ask how much it could cost you -being such a great place as it is- Paine might not be the place for you. Anyhow, try to make it