Comparison plugin for WP e-commerce

I want to build a Worpdress shopping cart using getshopped.org plugin. I want to be able to compare the cart’s price for each product listed on the product page to Amazon’s price for that product. For example, the store sells Mabo geiger counter for $23.00. I want customers to be able to click a hyperlinked “compare on Amazon” button to view Amazon’s price for Mabo geiger counter.

https://wordpress.org/plugins/wp-e-commerce/