+ How does shipping work on eBay?
  Ebay's shipping workflow is integrated with the USPS, so when sellers choose calculated, 
  buyers will see the shipping cost based on the weight, class of mail, seller's zip code, 
  and their own zip code. You don't even have to think about it 
  ¡X eBay and USPS will calculate the shipping cost for the buyer automatically.

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