Create an Event Ticketing Website

I am looking to create a website that essentially offers the same service as other sites such as [login to view URL] or ticketleap.com. The site would allow users/customers to create their own page on the site that allows them to sell tickets to their own event on this website. There is a service charge to the user/customer (which goes to the site), plus credit card processing fees, and the rest of the money goes from the ticket buyer directly to the ticket seller (user/customer). I would consider, to start out, cloning a similar website, and then making aesthetic and functional changes based off that initial framework. I would rather do it this way because I believe it'll be more cost effective and easier / simpler of a job to do. -- Additionally, we would probably need additional work done once the site is online, in order to maintain / adapt / grow the site. We already have a significant customer base lined up for as soon as the site goes online. If you are interested I would like to speak further about what work would need to be done, what the cost would be for the work, and what future opportunities there might be after the site has been built. Price / services are negotiable, so don't put much weight on our selected Budget. I am also interested in any other advice or opinions you may have based on what we are trying to do.