I am curious about this one, as I read this post a bit (http://community.gemsofwar.com/t/traitstone-cost-in-pictures/14541) and here is something that confuses me.
When I have a white card the first bonus costs like 10+4 of the lowest two stones to unlock.
But what if I have 6 of that white card and upgrade it to green? does it still cost 10+4 then or does the green cost apply from now on?
If the latter is true, it’s like shooting yourself if you upgrade any cards before you unlocked the cheapest possible bonus skills!