Like most Magic: The Gathering cards, the value of Conduit of Ruin 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 (Battle for Zendikar Promos)
They also allow bulk submissions (e.g., 50+ cards) at even lower rates, sometimes as low as ~$12 per card for large batches, making them great for grading lots of modern cards or sets
Generally these phrases are used as intended by saying things like Well Played after the game, but they can also be used to taunt the opponent by saying things like Well Played after your opponent makes a huge mistake
While not abundant, reds graveyard hate cards can provide crucial disruption in specific matchups
The Pokemon trading card game was a burgeoning new sector of the fast-growing craze that was, at that point, still confined to Japan