Mono black decks dont really get to ramp very often, and one of their primary ways is sacrificing creatures but they need mana producing Altars, or a creature like Pitiless Plunderer in play to really pull it off
Once a creature you control has been blocked, changing its power to 1 or less won't cause it to become unblocked
Instant-speed removal is just so important, and Grasp of Darkness kills basically every threat in Standard at the moment for the low cost of two mana
Near the beginning of what we call series, based off the latest video games that came out, we really try to take care to stay true to the video game that we're basing the card series on, says Nagashima
But thats done the Grass-type starter just fine
Im saying that from a PURELY INVESTMENT viewpoint, be careful sticking too much money into the newer stuff because the production runs are WAY bigger than the Gold and Bronze era sets