Silver Booster Pack
A Silver Booster Pack contains one random silver card as well as two random support cards or upgrade cards. They can be bought for 35,000 Power Credits each. They are rather unpopular, as the Starter Pack is not much more expensive on Android devices (50,000 credits) and offers a far more powerful gold character as well as two silver characters.
Silver pack contents

Possible contents from a silver booster pack.