The leveling up of cards should certainly be revisited. The cost of leveling up outweighs the marginal utility of leveling up.
Plus the bcx cost per level doesn't make much sense (1,5,9,14,30, 60...) seems just like some random numbers they pulled out their butt. Should have been (1,2,4,8,16,32,64,128,256,512).
Hell, I would even get rid of the max level, combine an extra 512 cards and get an extra health, speed shield.
As for pricing, to reduce the cost of packs I would increase the burn value of the cards from 10x to 100x.