107731 Auction Site

I want a site built based on auction. It worked where the more people who bid or bought a product the cheaper the product became. It is for auction where the more ppl buy a product the lesser it cost. An example is where i would be able to list a product such as a Computer and i have 1000 to sell. It would start out at say $700.00 however depending on how many people were interested the price of the computer would go down. So lets say that 10 people bid on the computer the new price would be $675.00 20 people $650 etc.(all 20 people would get it at that price) The people who bid are comitted. It would also be cool to see how many more bids have to be made before the next price decrease. I would also like it to be an option where the auction will end once all pieces have been accounted for. . In the backend i would have to be able to contorl what discounts depending on how many bidders. The concept is a whole bunch of consumers bidding on items to bring the price down instead of up. Please show me ready made script if you have.