The CTA token price in pack is about 0.50$ (transaction cost add in pack price).
But if you purchase a premium pack (Apprentice, Disciple, primus) you can have a discount of 74% on your first pack purchased !! The CTA token will cost only 0.13$.
More you stake CTA tokens, more benefits you have.
As you can see here, you have 8 tiers, staking from 10 to 7000 CTA.
Tier 5 give you a weekly free withdraw SR card, tier 6 give you 1 more card and tier 7 give you 2 more, for a total of 4 SR cards !