You could theoretically use AIM to charge $0.01 and then immediately void it to validate the credit card, then set up an ARB subscription to charge at regular intervals. I don't think you can change the interval of the subscription later, however, just the amount:
• The subscription start date (subscription.paymentSchedule.startDate) may only be updated in the event that no successful payments have been completed.
• The subscription interval information (subscription.paymentSchedule.interval.length and subscription.paymentSchedule.interval.unit) may not be updated.
• The number of trial occurrences (subscription.paymentSchedule.trialOccurrences) may only be updated if the subscription has not yet begun or is still in the trial period.
Your best bet if you are doing subscriptions that change a lot over time is to implement CIM (Customer Information Manager). This allows you to set up customer profiles and payment profiles and then bill for any amount at any time. There's also a validation mode that automatically does the $0.00 or $0.01 charge up front and then immedately voids it. So you'd just turn on validation when you create the profile, then have an automated script that runs every morning and generates a charge for members whose subscriptions are due. The interval and amount can be anything you want.
