Timetable of ferry to Sakurajima

Is there a time table of the ferry service from Kagoshima to Sakurajima and return ?

Any onsen (and price ?)to visit in Sakurajima near the tourist information centre ?

Is there a time table of the ferry service from Kagoshima to Sakurajima and return ?

There are frequent connections 24 hours a day:
http://www.sakurajima-ferry.jp/timetable.html

Any onsen (and price ?)to visit in Sakurajima near the tourist information centre?

Yes, there is one onsen bath, but I personally did not find it very nice. It was very crowded and the baths were not very nice. It costs 300 yen:
http://www.rainbow-sakurajima.com/onsen/index.html

Furusato Onsen on the other side of the island is much nicer, but also more difficult to get to:
http://www.furukan.co.jp/furo.html
http://www.furukan.co.jp/access.html

What is the return cost of ferry from Kagoshima to Sakurajima ?

150 yen one way for a person.