Build an Online Store with provision for unlimited number of sellers

Though the project is small it has excellent potential for continued monthly maintenance contract as long as the site is on the web. Payments will be made once the project is done and online, any type of guarantee for timely payment will be provided when required. This is a website which will have unlimited number of Sellers displaying their product for sale and payment gateway may be through the main website or direct. Please provide information about your past experience, organization strength and time required to finish the project.(example- [login to view URL]).