MArcomage

For resources, do you mean "stock" or each resource specifically? Either case, wouldn't this zero-cost uncommon card be too powerful? The total cost in hand can easily reach 50(unless its a zero-cost deck), 50/5 would give you +10 stock if that was the case.
Nevertheless, I like the idea of total cost in hand.

Of course it needs balancing.

But the point is that every resource is counted independently.

So it will give more recruits to soldier or beast deck, more bricks to unliving etc.

Maybe it needs some limitation.

Or same amount of resources will be given to enemy.

Or resource gaining will be lowered by fixed amount.

Or maybe it must give only one resource type - with highest possible income.