Weird transaction

Description

I’m selling a lamp on eBay and the guy send me this Alright i want the item to be shipped to my nephew in New Orleans with a 300$ Google play gift card because it is to be presented as a birthday gift,I’m currently not available to have it done my self because I’m out of the state with the marine corps for an international duty so I’m making an additional payment of 400$ which is 300$ for the gift card,50$ for the shipping and 50 for the inconvenience, I hope you can kindly assist me with that? Is there a way this could be a scam? Thoughts?