You can safely store the user’s saved CCs in the database by grabbing the anonymized stripe card id that’s returned when create the first charge. This card id points to the user’s credit card that’s stored in stripe and can be used again by the stripe plugin to charge that card at a later time.
You simply need to store the stripe card id in your database and your max charge amount and create the interface and logic to allow the user to pick their card and restrict it if necessary.
Create a new data type called (lets call it card) in your database
Create fields for stripe card id and max charge amount (and any others)
Create a relationship between each card entry and your user. I suggest a list of cards for each user
What you wind up with is structure to your database and app where you can create conditional logic to do what you want: