Like most Magic: The Gathering cards, the value of Rhystic Study depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (The List)
And that gives opposing stuff a level of resistance against mass removal
New entries usually come in after a major event (worlds, regional finals) or after a meta shift makes a previously-quiet character relevant
None of the non cube cards in this list will be migrating into the cube as a result of this deck
Even casting it for its prototype cost is fine getting a three-mana 3/3 with those abilities helps prevent aggressive decks from getting out of hand
Trample is broken with deathtouch, since you can deal just one damage to each creature that blocked it and overflow damage to a player, so I have a few ways to grant it