Yeah, I don't actually rent any cards. I've basically been biding my time and saving my DEC for the SPS airdrop and then I'll work towards getting a really strong collection and start playing in the tournaments.
At the moment I'm really just finishing my daily quests and trying to get into Champ III.
At that level, I can't get close to finishing the quests unless they are in my "easy splinters". I had a water quest. It just sat there for days :D