When you buy multiple items from a seller you can or will get an option to ask the seller to conglomerate shipping charges by Ebay. If you select this button you are then making it so you are obligated to buy the items before this question is answered from the seller.

Buying multiple items and option to ask seller to conglomerate shipping | Ask a Mentor

Buying multiple items and option to ask seller to conglomerate shipping | Ask a Mentor | eBay Community