I can see that this can be read 2 different ways... and a full stop and an extra word is probably required:
"NB: If purchased with PayPal this will constitute an annual subscription. This payment is controlled solely via your own PayPal account."
An annual subscription payment is alerted via an email to the member and then automatically deducted from a PayPal account (and prompted for manual transaction in the case of EFT). Whilst we are extremely appreciative of all the various member's financial support, we also try to make it clear that these PayPal payments are controlled solely by the member from within your PayPal profile settings and we have no control over this annual deduction.
I've made a note about this and we'll make it clearer in the near future...