I found one (half-fare) on the sbb.ch site for 20.50 CHF, but my contact said to buy a ticket on the Swiss Travel System website for 110 CHF.
Well, Half-Fare card it's special discounted card which gives you 50% discount on rail travel in Switzerland, but it is useful only in case you are living in Switzerland or plan to travel a lot, because the price of such card is rather high, thus you need quite many journey so it will pay back.
In you case it's not worth it, better just to purchase regular one-way ticket Zurich Airport-Valendas-Sagogn. Valendas-Sagogn is the closest railway station to Laax (if you mean municipality in the district of Surselva in canton Graubünden), it cost 49 CHF (have no idea how you found those 110 CHF
). On SBB website ticket Shop you just need to choose the following:
and then continue. Or same ticket can b easily bought at the train station in the airport, thus no need to worry at all.
In case you want a direct ticket to Laax, then just enter Laax instead of Valendas-Sagogn, SBB will sell you one through ticket (by rail till Chur, while in Chur you will need to switch for the bus till Laax. Such through ticket Zurich-Airport-Chur-Laax will cost you 56.2 CHF