It's a pain to find Black Friday sale items that we don't own yet. They all have the "Add to cart" button enabled.

I can click an "Add to cart" button and it still shows me "Product was added to cart" even if I already owned it.

And the button changes to show "Added to cart" with a green checkmark:

Only once I go look at the contents of my cart do I see that several of them were removed.

This is a waste of time. I'd rather only click on the things I don't own already. It's especially bad for someone like me who probably owns almost all of the commentaries that are on sale already. I'd love to pick up any that I might be missing, but the process for finding those is time consuming.
EDIT:
Please note how you do it correctly for other sale pages (this is from the monthly sale for November). Now "go and do likewise" for Black Friday.
