Return train from Zurich airport to Meiringen

1. Is it cheaper to buy a ticket in advance on-line or wait until in the station on the day? It would appear to be the same price to buy a return ticket as two single fares?
2. Given we are staying in Meiringen for 8 days (arrive Sat, leave Sun) and we intend to buy a Bernese Oberland Regional Pass (only has 8 or 10 days not 9) which includes Lucerne where we change trains on our in bound and out bound trips would the following seem sensible? Buy a single ticket from Zurich airport to Meiringen. Then on the next day buy an 8 day Pass which would include the train ride on the day of our departure to Lucerne. Then in Lucerne buy a single to the airport back at Zurich?

Many thanks.

Hello Pottermus, welcome to MySwissAlps!

1. When you buy doesn't matter for the price, although sometimes buying online might be slightly cheaper or more expensive depending on exchange rates. You can have a look here. Two single fares costs the same as a return fare, but return tickets should be used within one day.
2. Yes, that would work. However, I would recommend to buy the pass online through www.swisstravelsystem. co.uk /en/products/ regionalberneseoberlan dpass (free delivery) and buy the ticket Lucerne - Zurich airport in Meiringen instead of in Lucerne. That will save you time.