It's too soon to tell, and it will depend on how rewarding defeating a Battle will be in the development of matches
If you want everything to take a healthy dose of 10,000 damage, Chandras Ignition is the card for you
Well now the most expensive - Undercity Sewers - is up to $25 and half the cycle is over $10
If you add a sacrifice outlet to your deck in the form of High Market or even Victimize, then you have a chance to really blow people out in any game
Estrid, the Masked 1GWU Legendary Planeswalker Estrid 3 +2: Untap each enchanted permanent you control
Granted, not all rare cards will be valuable, as they also have to reach the competitive or aesthetic standards that players and collectors have, respectively