Sorry Helston for going a little off topic... :
Imo DR shields should be as cost efficient as weapons are, because you can only play 1 at time no matter how many of them you have in your hand...
I mean, if you want a fahren/discord in your fire deck/denial deck you have 2 options:
1. build a deck with lots of them to get them early, in other words you get the risk of having dead cards in your hand for more consistency
2. build a deck with few of them to get them if you are luck, opposite of the item 1, you sacrifice consistency to have less dead cards in your hand
with dr shields this just dont happen, you usually dont want them consistently because they dont do as much as weapons
for example, vampire dagger, it costs 3x less than vampire and do 2x as much as them, you can say that this card is like 6 vampires in just 1 card
morning glory: it costs 0,16x less and do 1,75x more damage then a immortal
sword (the other card): it costs 3x less then a flesh spider and do the same damage, excluding the fact that it costs random quanta
these are all good, cost-efficient effects, i guess you can say that weapons ara balanced beetwen themselves, now if you compare shields...
"countdown" shields (dimensional shield, wings, bonewall) are so strong that they alone can win you a game against a unprepared opponent, on top of that these cards are meant to be used in numbers, this means that they have good effects, you will also draw them consistently without having to worry about dead cards and with many shields in your hand you can react better to your opponent counter plays (pc for example)
whereas DR shields have meh effects and you lose alot of your hand if you want to draw them consistently
its win-win vs lose-lose scenario...
I agree with the op about the cost reduction, maybe make it cost even less quanta, like 2
/ 4
, and it will still be balanced if compared with weapons