AND, it should be noted, the "FROM $209/night" wording is only on the screen where you choose a property. Once you've selected a property, and you're on the "choose a room rate" screen, that wording is gone and it just says room type X is $Y, even though the actual price will almost certainly vary significantly!
On that "choose a room rate" screen, if the rate changes during the stay, there should be a comment on that rate. Just under the room type description there is a statement stating that the room rate changes on XXX date to $YYY.
So the system is letting you know there is a rate change within that stay and what that change is. (At least that is what I see when I search for rates.)