Custom component for Joomla (credits system + payments)

A simple component is required for Joomla 2.5 that will allow users to purchase credits (virtual money) through eCommerce (PayPal), automatically update user balance (number of credits) in the database as well as provide a method to "charge" users for a paid service. Each service will be "worth" a certain number of credits and it will be delivered as some workflow step (like showing a specific page or triggering an email) as soon as user confirms their "virtual payment". Component must have configuration area where Services can be added and assigned their "value" (e.g. 25 credits, 50 credits, etc.). Admin must be able to view/update user's credits through the back end. Also a module must be created to display user credit balance on a page (their profile page, for instance) along with the "Purchase credits" button. Configurable options to purchase pre-defined amounts of credits must also be provided (e.g. 25 credits, 50 credits, 100 credits, etc.). Configurability is important for this project. _Note:_ There is existing Joomla extension called Vodes which apparently does most of what is required although it seems like it hasn't been updated for awhile. It is expected that it (or a similar extension) can be used as a starting point and customized to meet the requirements - rather than writing everything from scratch. Preference will be given to users who have extensive experience creating and customizing components for Joomla. Note 2: User profiles are currenly managed through Community Builder.