Jun 30, 2016 - 7:02 AM
Apart from 10 km around St. Moritz, that route is exactly the same as the outward journey in the morning (assuming it is all by train). You can check the map here and here. If you want more variety, the route I suggested earlier is better. Another option is to return via Sagliains - Landquart. Still part of it is duplicate.
Yes, it's free, see the map: myswissalps.com/ swisstravelpass/ validity. I can't really comment on the prices you wrote about until you let me know which website you were using. But it's not important as you do not need tickets anyway. Note that a quoted price might be related to seat reservations, which is a separate amount if you choose a train that requires you to book seats. If so, $28 could be about right. Most trains do not require seat reservations, but the "official" Bernina Express does.
Last modified on Jun 30, 2016 - 7:06 AM by Arno