See my posting about the seller's feedback. If and when your package arrives, photograph the unopened package, especially if the weight and size seems off. Include a ruler in the photo for scale. If the package seems light or weirdly heavy. take it to the Post Office for an official weight.
Two years ago I ordered a GoolRC GPS drone through Walmart (drone, controller, 3-batteries, and a case) for about $250. It was sold through a third party vendor. When it arrived, the package was way too small and too light. I did what I SUGGESTED and the package contained a battery charger, not a drone.
The vendor said they had proof that I received my drone, but I had the photo of the unopened package with the shipping label and the PO's official weight of only a few ounces as proof the the package they sent was not the drone...
I did get a refund of my money from Walmart in about two-months. The vendor's listing remained up on the Walmart web site for about another year and "strangely" I could never leave a negative feedback...
I hope you get what you ordered, but take no chances, the seller has never sold a drone previously. If all seems good, be sure to buy the Care Refresh from DJI when you activate you drone, do not waste your money on other 3-party policies, they do not offer Fly-Away coverage an if you crash it and they fix it, the best you can hope for is a rebuilt used one...
And I hope your drone does not turn into a case of "Witch Hazel..."
Good Luck!