Selling on Amazon and Ebay – associated costs

Hi all

In terms of how the site interacts with Amazon, Ebay etc how does this work in terms of fees etc.

I see Ill need the “Amazon and eBay Integration for WooCommerce” extension which is 29 dollars per month (+ 1.9% on Marketplace sales). Do I also need to pay Amazon and Ebay fees on top of this? (if so, are these charged per transaction?). Are there any other costs I need to factor in?

Does the Woocommerce extension automatically take a feed of my products (stock count etc…) and display them on my Amazon and Ebay pages?

Thanks