you will need your domain name and hosting which will cost around £50 for something decent. If you dont have the programming skills then i suggest you pay for a template or a web designer to design your website as appearance means alot. Then it is up to you to find the right suppliers at the right prices for those products.
You may want to integrate SSL into your site for secure payments and obtain a merchant account, paypal and google checkout as these are good to integrate but most of this costs money, possibly a few hundred pounds.