Turning dead cards into action sounds like the perfect use case, though I've seen this be used in a deck that tries to go off with Phyrexian Dreadnought and Greater Good, with some Replenish action, too, hence the two-dollars-and-change price tag
The only downside is that these arent a deck can play any number cards, so you cant run them all in Commander
If the creature you control already has a Role that you control attached to it, that Role will be put into its owner's graveyard as a state-based action after the Monster Role is attached to it but before the reflexive triggered ability resolves
After redeeming the gift card, they will be able to use the balance to purchase MTG Arena Codes on the site
Every card you care about even if its not super rare should live in a sleeve to prevent minor wear
Fast lands tend to be great filler lands to bolster an otherwise fetch land-centric mana base, especially for more aggressive decks