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The Buyer PayPal Requirement information is stroed in Item.BuyerRequirements.LinkedPayPalAccount property if the data is available. The property is returned in GetItem to any valid API requester. However; the Reserve Price value that stored in Item.ReservePrice property is a private data and only reported in GetItem if the API requester is the seller of the given item.
The BuyerRequirements.LinkedPayPalAccount property is returned as below: