Buying cards

[Malduk]

There's always an option to make neutral NPC sell chosen cards that are important for giving strategy options to teams (in deckbuilding). Like explosions, momentums, lightnings etc.

[Dragoon]

Type of Card	Specific cards	Cost
Rares	All elemental weapon cards	Cannot be bought.  Only quests and special buildings can give this.
Semi-rares	All Alchemy cards	24
Expensive	All dragons and ...       Nova and Lycanthrope       Poison and Mummy       Momentum and Sapphire Charger       Earthquake and Graboid       Heal and Horned Frog       Immolation and Phoenix       Freeze and Toadfish       Miracle and Pegasus       Fog Shield and Firefly Queen       Golden Hourglass and Pharaoh       Steal and Devourer       Fractal and Phase Spider	10
Regular	Everything else	4
Quanta Sources	Pillars/Pendulums	2

Just an idea.  Cards of your element sell for half in your own element's cities (1/2/5/12).  Every city carries cards for 3 elements (their own plus their two neighbors).  Outlaw City carries all the cards but are at a 25% premium (3/5/13/30) except for Other players.  I tried to pick the two most popular cards (one creature and one other) from each element for the Expensive category.  I'm sure it's debatable.

[Kamietsu]

Type of Card	Specific cards	Cost
Rares	All elemental weapon cards	Cannot be bought.  Only quests and special buildings can give this.
Semi-rares	All Alchemy cards	24
Expensive	All dragons and ...       Nova and Lycanthrope       Poison and Mummy       Momentum and Sapphire Charger       Earthquake and Graboid       Heal and Horned Frog       Immolation and Phoenix       Freeze and Toadfish       Miracle and Pegasus       Fog Shield and Firefly Queen       Golden Hourglass and Pharaoh       Steal and Devourer       Fractal and Phase Spider	10
Regular	Everything else	4

Just an idea.  Cards of your element sell for half in your own element's cities (2/5/12).  Every city carries cards for 3 elements (their own plus their two neighbors).  Outlaw City carries all the cards but are at a 25% premium (5/13/30) except for Other players.  I tried to pick the two most popular cards (one creature and one other) from each element for the Expensive category.  I'm sure it's debatable.

That looks nice, except Miracle and Pharaoh are actual rare cards, and should be included in the Rare (Cannot be bought) list. All rares should be, in my opinion.

But how to deal with shards? Should they be something extra, or special, or grouped in with the rare cards? Or not included at all?

[Daxx]

If shards are included at all, I imagine they'll be super-rare cards that you only win after a long side-quest chain.

[Dragoon]

I don't think Shards should be included personally.

As for rares, honestly, I don't find Pharaoh, Miracle, and Arctic Squid so strong that they should be more rare than the other cards.

Edit:
Had another thought, since not all Alchemy cards are as desirable in deck-building (ie Aflatoxin), you can make it that when they buy the Alchemy card they not only get the in-game card, but they also get an in-WoE item as well.  We can make these items stronger or weaker to help compensate the weakness of an Element's Alchemy card.