from the previous link:

Sellers must not:

• Fulfil orders via a third-party service when the above conditions are not met. For example, the Fulfilment by Amazon service does not satisfy the third-party fulfilment conditions under this policy
• List an item on eBay and then purchase the item from another retailer or marketplace that sends it directly to the customer – this includes presale listings
• Misrepresent the location of their stock, as this violates our Item location policy