Make registration process in one step (registration and subscription in one step)

Hello Sir,

I am using your membership plugin in my job sharing membership site with buddypress.

What i want to do is simplify the registration process in one step, i want to add the paypal subscription button on registration page, so user can fill details like username, password, email and click subscribe button to become a member

i attach a screenshot of what i want to achieve below

Awaiting your kind reply....

Thank you