I saw on these
forums that the cheapest option to travel from Zurich to Venice would be to get a ticket via SBB from Zurich to Milan and then get another ticket from Milan to Venice. The cost from Zurich to Milan this way is 85.5 CHF (I have Halbtax).
I noticed that there might be a cheaper option. I can go from Zurich to Chiasso for 35.5 CHF and then take a train from Chiasso to Milan (which I heard is 20 CHF at the trainstation? -
http://www.rome2rio.com/s/Chiasso/Milan). Does this seem legit?