Build site that buys old cell phones

Hi, I would like a clone site of [login to view URL] but with a better frontend appearance. I need the site to have some sort of easy control panel for account/billing information to keep track of what phone sdiffrent users submitted, as well as an easy way to add new phones to the database, as well as adjsut their values ($). I would like it if the site could at least start out with the same database of phones that the site reffered to above has. My budjet for this project is about $100, and that neededs to include istallation on my server.