I probably screwed up, because I bought this at $800 (with no card discount showing on the receipt or website — I chose “IHG Premier MasterCard” payment method, and nothing changed from any other card) assuming that the discount was just silently handled in the payment stage.
The terms and conditions in the email I received promote the 20% discount seem to align with my interpretation, but it seems like others were seeing the discount explicitly reflected…
Upon completion of the points purchase, you agree that the total dollar price of the points, minus the discount, will be immediately charged to your credit card.
I’ll see what ultimately posts, but I assume I’m going to have to fight with them on this.