Supersaver ticket on sbb.ch?

I tried to re-create your search but didn't find myself on the screen you linked, so I'm not sure what's going on. Haven't been on a Swiss train in ages. It's possible that the 30-euro fare is for those using the half-fare travel card, but calling it a "supersaver" fare seems odd. One thing you might try is clicking on the tiny "i" to the right of the text, "% Supersaver ticket, save up to 50%", that's above the list of travel options. I've seen hotel websites where doing that brings up things like the cancellation policy.

I click no reduction and it still takes me there. This is what the "?" brings up:

Supersaver ticket.

Supersaver tickets.

There are supersaver tickets for 1st and 2nd class. Offer based on
availability. You can obtain supersaver tickets with a discount of up
to 50% on the standard price and on the reduced* price (with Half-Fare
travelcard, for children from the age of 6 up to their 16th birthday
and children traveling alone under 6 years). Children under 6 years
accompanied by an adult travel free of charge. You can buy a
supersaver ticket with a discount (Half-Fare travelcard) for 2nd class
for your dog. The ticket must be registered in the name of the dog’s
owner. Validity. The supersaver ticket is only valid for the selected
date of travel and the selected public transport connection (train
connection). Special conditions. The number of supersaver tickets is
limited. Supersaver tickets are available for most public transport
routes except routes within a regional fare network. Supersaver
tickets may be purchased no more than 30 days before the desired date
of travel. You can purchase supersaver tickets at the SBB Ticket Shop
to be printed out as OnlineTickets by the purchaser (print@home) and
now on your smartphone via SBB Mobile. It is not possible to upgrade
class, change routes or change trains using a supersaver ticket. The
Junior or Grandchild card is valid in combination with the supersaver
ticket. Price, product and timetable information is subject to
modifications.

Super Saver tickets are offered between certain city pairs, generally in the off-season. They are unrelated to a Half-Fare Card. You can see the conditions and cancellation policy by clicking on the little , "i" as suggested above.

I find it very odd that you can't get the same page. These are the steps I did:

Go here: http://www.sbb.ch/en/home.html

Search for Basel SBB to Interlaken OST on May 16th, starting from 13:00. Select no reduction. It should be there, I'm not even logged in so there's no reason it would appear just for me. Unless they are IP checking and doing this on a country basis, which I doubt.

I also forgot my login data and they won't send it to me via email no matter how many times I request it.

I went ahead and purchased it with a new account since SBB won't send my data. Comparing it to my Lauterbrunnen-Venice ticket that I also bought at SBB the only difference I see is that the supersaving one doesn't include a reservation. There are no seat or car numbers.

That's because this journey doesn't require a reservation, and not because I paid less, right? I just show up and choose any seat I want?

I only pay for reserved seats on European trains when they're mandatory. I doubt that you need to do that for the Basel-Interlaken run. However, I found this information on the SBB web page: "Seats...You can reserve your seats on Swiss trains in the SBB Ticket Shop, using SBB Mobile on a smartphone and via Rail Service 0900 300 300 (CHF 1.19/min. from the Swiss fixed-line network) or direct at the ticket counter. It costs CHF 5 per seat to make a reservation."

Seat reservations are not included in the price of tickets for travel within Switzerland and they are not mandatory. We have never paid to reserve seats in over eight weeks of travel in Switzerland. The one and only time this caused a problem was the day we were heading to Zurich airport on the day of the Zurich Love Parade. About a million people show up. The train from Bern to Zurich was very crowded (we could not find seats) but at least the people were dressed in entertaining fashion. Think feathers, paint, and occasionally tinfoil.

Good to know, thanks!