The refugios open during the month of September are Lodge Paine Grande, Refugio Los Cuernos and Las Torres. The regular buses start on the 1st of September and the catamaran on the 5th of September on every Tuesday and Friday at 12:00 from Pudeto to Lodge Paine Grande and return at 13:00 hrs all connected with the buses.
The round trip ticket is CLP $18.000 and one way $11.000 for the catamaran where you pay the tickets on board. For the buses they start at $15.000 round trip, but it can change, my personal suggestion for secure, punctual are Buses Gomez and JB in that order.. but shit happens… 
The Entrance of the National Park Torres del Paine is CLP $ 15.000.