price comparison(similar to amazon)

Hi guys!

would like to know is there any extension/module that is similar to amazon price comparison? for instance, i posted my own pricing for the certain item. upon clicking on the item, it bring me to the item page with detail, pricing, photo etc etc. within the page, i would like an additional function whereby it can capture customer data which is also selling the same item as me.(i explain this further) It would show something like 3 customer selling if 3 of them selling the same thing as me. and upon rolling over the sentence, it will roll down the list of customer with only their contact number, username, name, and their selling price shown.


Basically, our ecommerce website is not only meant for ourself. we also like customer members to sell their stuff. However, they can only sell items that we had already stored in our database.(at the member selling page, there will be an option for them to choose the item they want to sell. The item list will be retrieve from our database)
If they want to sell other items which does not exist in our store, they can email to us and we will find the product for them and upload into our database before they are able to sell it.


I'm searching for someone that is able to do this. if this extension/module doesn't exist and you are able to create it, please get back to me. willing to pay at a great price for it.

Cheers

i think everyone looking for this i see at least 3 post about this aswell