The new RSMembership! revision comes with an important number of added functionalities : the One-Time Payment Settings option, the Custom fields tab and the Trial periods for memberships.
One-Time Payment Settings
Beginning with the rev. 11, you can find new options for one-time payment: you can set different prices for renewals, when creating a new membership in the Joomla! backend panel.
So, when a user wants to renew his membership, he can now pay a different price than he did the first time.
Also, here you can configure the membership coupon discounts - coupon codes and prices.