Build Facebook E-Commerce Application

I would like to create a Facebook application that would allow a Facebook user to integrate a fully functional store front/E-commerce to their profile. This application should be secured, easy to use, flexible, and appealing. The ability for users to view analytics would also be nice. Please provide a quote for the application and what types of functionality that should/would be included. I would also like some information as to how I would have control over and market this application and change some aspects of it in the near future, if need be. Please don't hesitate to ask any questions. If the budget constraints are too tight, please let me know and we'll try to work something out. Thanks!