From Santiago to Patagonia by bus

Ok. Here are the real data experienced in april 2009. You can find the airplane ticked for few hundred bucks round trip, but you will not know what is the Puerto Montt like and you will not see the beautiful scienic views of chilean and argentinian Andes.

Santiago - Puerto Montt: the trip will last around 12 hours and if you are not chicken which needs the bed to sleep, you will pay 12000 CLP/16euro only.
Puerto Montt - Punta Arena: 30 hours sitting will cost you 30000/40euro. All the long distance busses in Chile are very comfortable with high standards.