Those price jumps are an indicator that the shop is using dynamic pricing, based on demand or based on other shops sales prices, this is nothing new and we unfortunately have to live with this.
The most ridiculous thing happened to me. I wanted to buy on Saturday and I was at the digitec store in St. Gallen. The customer support person said to me that, it is better to wait till Monday due to Cyber Monday and the price may decrease. I waited and to my surprise the price increased by 50 chf.