Unfortunately, this seems to be the case, you can look up the exact price development in the "Price development" tab. I suspect that in this case our "cheapest" supplier of the item has deactivated new orders and the calculation of the sales price has jumped to the next cheapest supplier. In such cases, such large price jumps can occur.

The price of this device is really absurd... it seems to fluctuate between 311 and 495 every week. That's a 60% mark-up if you're not careful and order on an unfavourable day!