Bus to Ainokura

Please tell me that where can I buy bus ticket at Takaoka/Fukumitsu/Johana station.
After finish travel at Ainokura,can I use bus to Suganuma and Shirakawago?
What cost of each trip (Takaoka/Fukumitsu/Johana station to Ainokura, Ainokura to Kaminashi,Kaminashi toSuganuma,Suganuma to Shirakawago)
Thank you for anyone who answer ^^

Please tell me that where can I buy bus ticket at Takaoka/Fukumitsu/Johana station.

You pay inside the bus as described here:
http://www.japan-guide.com/e/e2015.html

After finish travel at Ainokura,can I use bus to Suganuma and Shirakawago?

Yes, but note that it is infrequent. And you will have to pay the fare for the different sections separately.

What cost of each trip (Takaoka/Fukumitsu/Johana station to Ainokura, Ainokura to Kaminashi,Kaminashi toSuganuma,Suganuma to Shirakawago)

Here you go:
http://www.japan-guide.com/bus/gokayama.html

Thanks a lot for your answer, but i still cant find the cost of each trip.
And another question that How to go from Ogimachi to TAKAYAMA?
Which local bus can i take?
I tried to find it but not found T^T