Hello,
If it's a recurring payment, it's obviously $10.
Recurring means to pay the same price every determined period.
Changing the price is changing the contract and it means that you need to stop the recurring to make another.
More than than the recurring is handle by an external system (Paypal recurring) and there is no way to modify the recurring price of someone without its consent.
HikaSubscription base its recurring on the "original order" to determine what are the products it needs to duplicate in the new order so it will use the same price than before.
Regards,
PS : If you have question regarding HikaSerial Subscription, I warmly recommend you to use the "HikaSerial" section of the forum and not the "payment method" which is really far from your questions' subject.
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.