Munich-Kufstein is some 13 Euros for 99km single.
Kufstein-Ötztal is 120 km, so the fare should be some 15 Euros. So the fare
should be some 28 Euros single, perhaps some more if you use the ICE train
in Germany.

Attention: the train station is at the end of the Ötztal, the bus from
Ötztal station up to your actual destination should cost a few Euros more.

Hope that helps
Turan