Question about Dyson Humidify + Cool Formaldehyde PH04

So when I look at the price development then it is a cheek. Up until 9.11 it was 679.-, then by 20.11 it had shot up to 829.- and now it's 749.- On Dyson.ch it's also advertised as Best Price Guaranteed, although the price is also 749.-. I think it's a shame that Digitec is also involved. Moreover, it is all the more obvious because the price development of the products is visible...