GetPaid (Formerly the Invoicing plugin) is a lightweight Payments and Invoicing system for WordPress. It can be used to sell anything online via payment forms or buy now buttons that can be added to any landing page. It can also be used by freelancers to manage their Invoices or by 3rd party Themes and Plugins as their payment system. GeoDirectory currently uses GetPaid as its payment system
is there not an option for this in settings already or am i thinking of something else?