Ok I know the budget is low - sorry.
I basically an auction site where users can post an item for a small set fee and others users can make offers on that otem (yes like ebay) but the offers will not be money they will be for a swap with another item. So the offers will need to allow the user to list details of the item they are offering for the swap.
There will need to be full site and user administration in the backend of the site. Clean coding, css and SEO considered when building the site.
Bid, and post a clear plan of what you would do if you are chosen for this project.
Payment by escrow only on full completion of a bug free site.