Marshadow 146/132 is an elusive Illustration Rare card
And we do have a precedent for a recent run of Commander decks increasing in price several years after release: Commander 2014
Engle Standard Not Legal Alchemy Not Legal Pioneer Not Legal Historic Not Legal Modern Legal Brawl Not Legal Legacy Legal Comp
According to the official stats, Grixis Twin, Affinity and Jund are all topping the metagame with around 10% of the field, but a full 15+ archetypes make up the rest of the field, including Merfolk, Naya Burn, R/G Tron, U/B Faeries, Goryos Vengeance and Amulet Bloom
Its hard to play it in a very aggressive deck, when we cant use it to clear blockers out of the way, though you could potentially combine it with stuff like Stitched Mangler, Bounding Krasis, or Topplegeist to make it more reliable
If theres a word synonymous with fear in Magic: The Gathering, its Phyrexia