Each time the Commander returns to the graveyard, you need to pay the Commander Tax to cast it again
It'll tell you if you have enough duplicate cards and/or Shinedust
For operators at any stage, the single best move is talking to a team that has already placed machines in the venues you're targeting and knows exactly what those locations produce
Abeyance (T1, Ext, S, Block) Almost strictly better than Orim's Chant, as it allows you to draw a card plus shut down another deck on your opponent's turn if need be
If a new enchant world comes into play while another one is on the battlefield, the old enchantment is placed into its owner's graveyard
A PSA 10 version of a card can be worth two, five, or even ten times what the same card in PSA 8 condition commands, depending on how scarce high-grade examples are