Now I was wondering the same thing. I know for a fact that if you buy packs, it is better to take at least 12 pieces at a time, as one will not be of much use. Looked at what can fall out of the packs, came to the conclusion that the chance to get a very expensive card is also not great. So for sure you can reach your goal only by buying individual cards that are needed. Although there is always the possibility of luck.))
Judging by my calculations in this post, then the 36 packs I bought at the start were at a slight disadvantage, but they have raised the stats to the point where I do not need to buy anything to pass the missions at level 35.
Thanks for stopping by!
!PIZZA