Build an Online Auction site

Hi, I need a web site similar to ebay or any auction web site but I need specific features. Normal features includes user account, paypal/credit card service, user and seller ratings, live auctions, pictures, item description, charge for seeling, etc... and special feature will be a map showing where the auction is taking place, this means if I'm the buyer I see where the auctions are so I choose to bid based on the location of the seller, I can select an area of interest on the map that shows my location compared with the sellers location. If I'm the seller I set where the auction is taking place so the buyer will go there to pick the item. Project details will be provided later since I'm working on it. I need cost estimation that's why I put only 10 on maximun budged