Hi @sjdkauai, welcome to Pandora!
If you decide to upgrade to Pandora Premium during your 30 days trial of Pandora Plus, you won't be charged for Plus and Premium.
If you upgrade directly through Google Play, you will immediately be transitioned into Premium, and the unused portion of your current Plus subscription will be applied to that cost.
Once you've used up the remaining value of your most recent Plus subscription, you will be charged for your first month of Premium.
If you have any other questions, please feel free to let us know.
