My strategy has always been to hand pick the cards I want off the market rather than buying packs. Not as exciting as opening packs and receiving airdrops, but it's what I do.

I've hoping the new CL Legendary Summoner for Fire will end up boosting Magic attack since I have many strong Magic cards for Red. I'll definitely be a buyer if that happens no matter the cost.

So far I have earned 7 CL packs from loot chests in the past month and a half since I began playing again. These are NOT eligible for airdrops as only ones purchased in the shop are eligible. I'm keeping these packs as investments rather than opening them. Though someday I may give in and open them using the hundreds of potions I've accumulated from daily quests.