...which is why it should disappear completely after it is no longer relevant.
After all, stores don't leave their signs up after a sale is over. "Oh sorry, yeah - that was $19 yesterday. We sold a ton of them! You can buy it today for $26 though."
I had a similar situation with the Nexus 9 tablet.
"I should get a Nexus 9, I do a lot of Android app development on my Nexus 7 and it is getting long in the tooth, $400... not bad" -> Nexus 9 on sale for half-price on release day (limited quantities) -> Missed the release window -> "Nexus 9 just doubled in price, I don't want to pay $400 for one"
Rationally I recognize that the value of the Nexus 9 relative to the $400 regular price didn't change at all due to the temporary sale, but emotional-response-wise it doesn't matter.
After all, stores don't leave their signs up after a sale is over. "Oh sorry, yeah - that was $19 yesterday. We sold a ton of them! You can buy it today for $26 though."