How does Multisite Content Copier handle duplicates?

I am looking for a way to update pricing for products across my network -- would MCC do this?

For example, let's say there are 10 products (SKUs) in the main catalog and each of my network stores sells the same 10 products, plus 20 of their own. Now, I need to update pricing and some other data for the original 10 products.

Could I use MCC to copy those products to the network sites? Would it just update the pricing, or would it duplicate the products already in the system?