electronics always works like this, early adopters pay a premium, in return they get to use product early.
Technology advances, marketing conditions change, so prices eventually reduce for same or superior product.
They know early adopters will pay a premium, to get early, so day one price is high, especially when pre orders are selling out. Then after thats done the next job is to sell to those who didnt pre order, typically those people are more price sensitive and wont buy until prices drop, hence what will happen.
Of course early adopters got some exclusive stuff that late buyers wont get. Also sometimes later hardware loses features. So a newer xbox1 or ps4 may have less usb ports or something.