Q&A Plugin customization to make it pay to view

I have installed Q&A plugin on my multisite website. Here is what I am trying to achieve: Registered members should be able to post their questions and answers (and upload long answers as word/xls). They should be able to set a price for each answer. Other non-registered and registered users should be able to view this answer only when they pay X amount for it. Is it possible to re-write/customize existing Q&A plugin for this feature?