Hello Patrick,
Thank you for your question about updating your payment method. PayPal handles the subscription entirely, so if PayPal has your latest information, then you are good to go.
On a side note, iIf you ever want to unsubscribe, you can "suspend" your subscription instead. This way you are not charged, and can continue with the same price, which is locked in at $8.
Thank you for your continued patronage, and good luck on your snipes. :-)
bidslammer