By now it should be well known that there are time-limited promotions here from time to time. They are usually marked. If you don't buy immediately, it's your own fault and you don't have to complain afterwards. Some low-price campaigns only last one day.
By the way, I would recommend the new 35mm f1.4 GM. I sold my Zeiss.

Prices change, but such a big jump in price is quite extraordinary at Digitec, where a lot of things are done by AI nowadays. In Digitec's competition, the lens is still available for under 1000 chf. Unfortunately I can't give you a link because of the community guidelines.