Getting selling prices from Amazon

We can search on Amazon for books based on their ISBNs. Normally, we will use the default search page on Amazon and enter the ISBN. We can do this manually, but from a program or scraper, we should know the URL to request based on the ISBN. Let us go to the Amazon site and search for this book with the ISBN, as shown in the following screenshot:

The page generated after the search in Amazon will have a URL structure as follows:

http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=1783289554

If we search based on another ISBN, that is, http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=1847195164, we will see that it gives us back the details based on the 1847195164 ISBN.

From this, we can conclude that if we substitute field-keywords of the URL with the corresponding ISBN, we will be getting the details for that ISBN.

From the http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords...