I am looking to get some quotes on how much it would cost to program the backend to a price comparison site.

I have access to the API's of all of the big sites, but need somebody to do all of the programming so I can integrate these into a search engine on my site.

I am looking to do something similiar to the following sites:
http://isbn.nu/
http://www.addall.com/
http://www.bookfinder.com/

Basically I will need the xml data pulled from the booksellers like amazon.com, bn, abebooks, alibris etc. I have access to all of the API's and would pull the data into my site when somebody searches and insert my affiliate link so I get credit if the person buys the item.

Please post your approx. quotes on how much you would charge to do something like this.