Years ago I used an extension for Firefox called Book Burro. It was amazing. It simply put a box in the sidebar of Amazon search results and showed you local library holdings that matched your search. Unfortunately, Book Burro is no longer maintained.

Enter the Library Extension for Chrome (coming soon for Firefox). You can find details at their web site. https://www.libraryextension.com

Once added to Chrome, you need to configure it by adding libraries that are near you. After that, you simply browse Amazon and the results will show up on the right hand side of the item details.