Based on your 398.00 (it has gone up slightly for 2019) you will be riding in 2nd class. SBB sells 2nd class SAVER DAY CARDS for as little as 29.00 (valid for most of Switz.--but not expensive mountain railways like Jungfrau, Gornergrat), these can be purchased as early as 2 months before your travel date, you must be in possession of a half fare card on the day of travel (not day of purchase), the price varies but usually is < 49.00.
https://www.sbb.ch/en/travelcards-an...-day-pass.html see more details here.
PS: Saver Day Cards are valid for most local transportation throughout Switz.