Joomla VirtueMart + Community Builder Addon

Our client desires a community where artist can upload their music and sell them. Artist registers as an artist and adds an product (most of this is done) - Title - Description - Original File (this must be stored secure). - Preview (if there is no preview a preview will be generated from mp3 30 sec.). - Price - Extra info (like lyrics). Usergroups (this is already done) - Artists - Customers Customer will use default VirtueMart buy and pay process. Payment will be to our client account. Montly there will be a list per artist and sold items (so they can calculate artist revenue). Our Last programmer finished the Community Builder (for the usergroups) addon and the virtuemart product iD0. We use community builder so artist have a own profile page. Give us your best price. Extra work like the monthly list will be done when above is done. Current programmer will do that in a new project.