If you are travelling between Nagoya, Takayama, Shirakawa-go and Kanazawa, get the 3-day Shoryudo highway bus ticket at 6000 yen and it will save you a great deal (read on people). Alternatively, you can get the 4-day and 5-day pass at 7000 yen and 8000 yen.
Shoryudo route
Here are some tips that you MUST know before you buy the ticket.
1) Do buy in advance because the tickets are limited.
For my case, I tried my luck to buy it 2 days before my trip and it was unavailable for my first day in Nagoya. Hence, I couldn't use it for my transfer between Central Japan Airport to Nagoya. I think it would be pretty save if you buy 1 week ahead your trip (for low season). For peak, I guess you have to buy it as early as possible.
2) It's only available online.
Buy it at Japanican website and through travel agent outside of Japan. Here's the link for Japanican.
3) Please check the ticket pick-up point very carefully.
You will need to collect the physical ticket in person (with your passport) at selected pick-up points in Nagoya. For example, if you are travelling from Tokyo to Takayama (without stopping at Nagoya), it might be impossible for you to pick up the ticket.
3) It does not cover the bus route between Takayama to Shin-Hotaka Ropeway or Okuhida.
I have no idea why I would assume that it covers the journey from Takayama to Okuhida and Shin-Hotaka Ropeway. My mistake, it doesn't. So if you are going to Okuhida or Shin-Hotaka Ropeway from Takayama and it will usually take a whole day, the ticket wouldn't be of any use that day.
4) It does not cover the bus in Shirakawa-go
So I tried my luck and again, the bus driver was not fooled. I am referring to the bus in Shirakawa-go that takes you to the Shiroyama Viewpoint that costs about 200 yen if I remember correctly.
5) Make advance reservation
For my case, I tried to book for ticket from Takayama to Nagoya a day before, and it's fully booked! (I felt like punching someone). Hence, no choice I had to buy the train ticket instead of utilizing my Shoryudo ticket.
Throughout my trip, I only managed to use the ticket from Nagoya to Takayama *pull hair*. Instead of saving money, I was paying extra!
So, I hope that you've learnt through my mistakes. Happy travelling yo!
Traditional housing in Shirakawa-gō