Cards based on The Sword and the Stone reign supreme in value as of the launch of Shimmering Skies
Selecting one of three of your opponents cards is a lot better than drawing a single card
These broader heavy removal spells are not things you want to have to blow on turn three, you ideally want to hold them to take out a five drop or something
Unfortunately, Wizards of the Coast doesn't attach a defined MSRP to their Commander products, so there's some room for demand-based price inflation
The ground gets bogged down, people have ways to deal three, and stuff just goes wrong more than you might expect
Most black decks will play it, none of them will be excited about it, but theyll all be happy to have in most scenarios when they have access to five mana