Of the Zendikar creature-lands, Celestial Colonnade and Creeping Tar Pit are obviously the best, as they can give you an evasive beater to get those last points of damage through
Twinflame Tyrant, Herald of Eternal Dawn, and Bloodthirsty Conqueror Fracture Foils are also in the $200 range
Additional options would be Rob the Archives , Jeska's Will , Commune with Lava , Act on Impulse , and Reckless Impulse
Arcanine EX and Arcanine VMAX cards represent some of the most powerful and valuable variants available
In terms of mechanics, before a game of Commander starts, each player sets aside their commander before shuffling their deck
But if you have two copy spells, say a Twincast and a Reverberate, you can cast one, then cast the second and make those copy each other infinitely for magecraft