There is the difference between full- and half price. Full price (1/1) you have point to point ticket or also supersaver offers. You just need to select by the travellers "no reduction" and you'll buy in the correct pricing. So in this case: Yes, you can buy saver offers without half fare.
Then there's half price (1/2) which means you own a half fare card/subscription. You can also buy such a subscription when you arrive in Switzerland, but I wouldn't recommand you this, if you only staying for 3 days.
The difference between point to point and supersaver ticket is: With a point to point you're allowed to travel the purchased route once on the printed date. The supersaver ticket allows you only the selected connection and is neither refundable nor exchangable. The supersaver day pass allows you to travel the whole day in Switzerland for free.
Kind regards, VlaznimA.