Building a games website like Console Passion

I am looking for a quote for a website like www.consolepassion.co.uk I want people to be able to buy, sell and trade games. I need a forum on the website. Customers need to be able to create accounts, upload pictures of consoles and games. We need to process payments for people to put credit on their accounts, so we can charge them 0.20 cents per game listing. Please only quote if you have experience and a passion for gaming, consoles etc. I need your best quote and a time frame for project completion.