I don't know if this is true, but I've been many websites that actually claim that they have an extra deal they can't show you until you put the item in the car

I don't know if this is true, but I've been many websites that actually claim that they have an extra deal they can't show you until you put the item in the cart. I used to see those a lot a few years ago, not sure if it was a real legal thing or just a trick to get people to add it, but that was definitely a thing and not related to tax+shipping.