Once you max out the reward cards you can buy the normallys from the proceeds of the daily quests. Win win. Thats the dream anyway but it's better to put in the work now before the game gets popular. I'm the same as you but my the life splinter is my weak hand but i complete the quests daily and my reward cards are all around level 5/6 so its working well. My challenge will be to level up the summoners. They are all fairly expensive even now.
That is the plan so will keep playing and keep building up the deck. Tournaments are where the action is but you need a really strong deck up to level 8 to compete in the gold ones. That and a lot of legendaries.