Well, sales are sales, and as long as it's not a price drop, it's unfair to compare the value of a sale vs. something with a regular price. Sale prices should of course be considered at the moment when buying something, but when discussing the value of various products. AMD products are not the only ones with discounts, it happens to Nvidia cards all the time too. I've even seen GTX 1660 Ti at a discount below MSRP, and that card is just a few days old.
Additionally, many Vega cards have a poor cooler which makes them unbearable for most users.
So until AMD actually drops the price of Vega 56, and versions with acceptable coolers are actually available at that price, they are pretty much unsalable.