new section in bidding

hello, i have a site it is clone of [login to view URL] and i love to add a new section called selling websites and desiegs so the user but his design he want to sell or even any scrips he done so he will put his site or design or script then they will bid on it exactly like ebay but for these issues so the higest bid will get it i don't care if u use free script or not but u will integrate it to my site and also to be admin panel say fofo in your bid or i i will not take a look at it and there is a lot of scripts there my maximum budget is 60$ and i think u can do it for it regards,