A Working Knowledge of Card Conditions Condition moves price more than almost anything else on a single card, so you need to judge your own cards honestly before you list
The Grixis color combination isn't great at ramping mana, but vampires tend to be very efficient in their cost and rely on each other for benefit, besides, you are limited to casting one collected card on each player's turn, so it's not broken right
Scrying and keeping the perfect card on top, only to have it then be milled and dumped into your graveyard can be very painful
Room enchantments are a way to depict the maze-like expanse that has taken over the plane in a Magic card
They arent nearly as interesting as, say, the Secret Lair x Marvel drops with commanders like Storm, Force of Nature and Iron Man, Titan of Innovation