Servertastic Limited has a reseller program for SSL certificates. The program uses a points system as credit to make purchases. The more points you purchase up front, the lower the price. Yearly plans are also available. Servertastic tries to be as inconspicuous as possible with no emails containing branded materials. Resellers can place orders in the web interface or through the API.
The Servertastic API is built for developers or resellers and utilizes GET requests for placement, management and oversight of orders. Using the API, clients can place automated orders for their customers. Data defaults to XML but can also be returned in JSON.