Comparative shopping Client application

Hi, I'm looking in developing a simple client application (install) for a comparative shopping engine in Flex 3/Air application. similar example: [login to view URL] but of course more visually appealing and less intrusive as possible. The client will open only in predefined domains, according to URL parameters or Page title and display relevant results accordingly from [login to view URL] API (according to users IP US/EU). More specific details will be provided later. Important: I Must have full control of the code for later updates/changes (documentations). If you are able to do it, please state estimated price and time. Thanks.