Feb 17, 2016 - 7:18 AM
Welcome to MySwissAlps, Kim66!
A return ticket from Zurich airport to Mürren costs CHF 183.20. If you plan to make local trips only you're probably best off with a Swiss Transfer Ticket Combi. It includes that trip for free, plus 50% discounts on the tickets for day trips.
The Swiss Pass was discontinued in 2014. It was replaced by the Swiss Travel Pass, but the above mentioned ticket might be a better option for you.
To compare costs, please see here for a detailed explanation and a downloadable spreadsheet.