Rifeanaf64
In case your plan is to hike all the spots around Grindelwald all the way from your accomodation and back (or you prefer spending all the time locked in your room 😉), then there’s no point thinking about travel passes, as regular single tickets between ZRH and Grindelwald would remain the cheapest option.
Those options mentioned by RolandP above only start making sense with all those (sometimes very expensive) mountain railways/cableways etc. located above Grindelwald village.