Most sensible pass for bernese oberland hiking tri

I'd appreciate some advice on what would be most cost effective. Two adults arriving in Zurich on 7/1 and heading immediately to Interlaken for one night before spending five nights in Murren and then heading back to Zurich for one night before our return flight to U.S. During our time in the Bernese Oberland we plan to do day hikes using the funiculars/trams, etc. but not really venturing out of the region until we have to return to Zurich.