I'm not a member of this community, so I'm going to throw this out as a suggestion and see how many votes it gets.
Consider linking to isbn.nu, which queries a number of online booksellers and shows prices for all of them. (My current reading.) This is always my own choice these days, on Stack Exchange or elsewhere.
Be aware that links to Amazon have the possibility of raising money for Stack Exchange. Whether you think that’s a point against them or a point in their favour is up to you.
