swa66 - 1:11 pm on Oct 12, 2012 (gmt 0)
I'm not sure if the base affiliate agreement even allows you to capture pricing and use it at all.
The Product Advertising API's agreement allows it, but imposes limits on how you can use it.
See section 4(o).
Also note that the API is rate limited: you cannot just pass on every request ina 1:1 fashion to amazon to fetch the price, you have to cache it locally.
Amazon does have an API where you can get the pricing info from with a little programming.
Look for "Product Advertising API".
Ref: https://affiliate-program.amazon.com/gp/advertising/api/detail/main.html (every amazon instance (.co.uk, .de, fr, .jp, .... have their own agreement, their own details etc.)
If programming is not your thing, try looking for 3rd party tools, but make sure to know what they do.