Aether Storm is just here because I really like the art
Riders of Rohan allows you to add eight power toughness to the board for five or six mana and play around wipes by using Dash
Elesh Norn, Mother of Machines doubles the effect of permanents that activate when another permanent enters play, all while these same effects from being activated by your opponent with that much power to shut down an enemy's strategy, this creature is worth every penny it costs.
A full EDH deck of 100 cards sets you back $100
Sword of Fire and Ice says, Whenever equipped creature deals combat damage to a player, draw a card and deal 2 damage to any target. This only fires when you successfully hit an opponent with the equipped creature
Tournament legality should always be your primary goal, even if you know that this is a card being done strictly as part of a collection