For purpose of making budgeted travel easier, I noted the buses I took in the region of Los Lagos and Los Rios in Chile including the fares they charge in October and November 2018. There are always multiple options and some are quite a bit more expensive than others.
Puerto Montt a Puerto Varas
To get from Puerto Montt to the small German settlement of Puerto Varas it makes sense to take one of the small minibuses instead of a big car-bus of the well known bus companies. The blue minibuses leave from the terminal in Puerto Montt at the shore. They drive regularly starting at 07:00 in the morning. The fare for a ride to Puerto Varas is roughly 2000 pesos
Puerto Varas a Osorno
To get from Puerto Varas up North to the city Osorno, there are no direct minibuses so you will have to take an official bus from ther Terminal. They leave in the morning between 07:00 to about 08:30 am. Arriving in Osorno you can either get off some place in the city or ride to the main bus terminal.
Osorno a Anticura via Entre Lagos (direction of Bariloche)
There is a big variety of buses leaving from Osorno in direction of Samore or Bariloche along the carretera 215 but most of them will charge a large fare. they will charge the full price even though you will get off about 170km before Bariloche. There are minibuses although they dont drive very ferquently. You can take a direct minibus to Anticura for a fare of 2000 pesos or make a stop in Entre Lagos which is 1300 pesos and then take another bus or hitchhike to Anticura. If you will be hiking up volcano Puyehue you should ask to get off at kilometer 89 of the carretera 215 or if you wish to stay at the campsite Anticura you'll get off at kilometer 91. The minibuses leave across the street from the main bus terminal and drive quite frequently.
Getting back from Anticura to Osorno will be a bit more difficult. The minibus picking up people along route 215 only come by once a day in the morning. In October 2018 the come by km 89 at around 07:30 during weekdays and at 09:00 on Saturdays and Sundays. If you miss the bus you'll have to wait another night, hitchhike or flag down one of the big buses that charge you much more.
Osorno a Lago Ranco (coming soon)
There are buses leaving the main terminal in Osorno for Lago Ranco.