Buy a "24 hour day pass" from Zurich airport station to Binz for CHF 13.60.
This ticket includes unlimited travel in Zurich fare zones 110 and 121. It costs twice as much as a single ticket so there is no point getting 2 single tickets (the same is true for all journeys in the Zurich tariff area).
thx, the last time I had to buy a tkt I couldnt use the machine since I dont have a PIN attached to my CC, had to use the manned window and what a line. Hopefully at night it wont be so bad