A bought a gold version of each of the common CL rewards cards. I also bought enough commons of each to have 2 lvl 2 copies of the normal cards. I probably could have gotten them cheaper had I been a bit more patient, but I wanted to get to Bronze 2 as quickly as possible to start earning DEC again.

Also, I figure Gold versions of the card will hold their value well/better. They typically have/do in normal CCG games, there isn't a reason to think they won't here.