I purchased from Amazon because of their more flexible return and service policy. DJI can be extremely difficult to deal with when it comes to returns or problems. -Not that you'll be returning anything, but as an example, mine arrived with missing cables, in a factory-sealed box, and DJI put me through an amazing amount of technical gymnastics (-Take a picture of everything that arrived, then provide an invoice and proof of delivery...for a $2.00 cable!). I just called Amazon and they handled it.
You'll find many "deals" advertised. Make sure that accessories (-like batteries) are official DJI merchandise, and not cheap knock-off products. Also, use only DJI props.
Get a case to carry everything. It doesn't need to be an expensive case, just something to keep everything together. I use a bag that says "Dirty Diapers" on the side (-Got it from Wal-Mart). I put my REAL drone case inside the "diapers" bag. Nobody's going to steal your dirty diapers when your back is turned, but a fancy, high-impact drone case tacitly hollers "STEAL ME"!
Pay very careful attention to the orientation of the charging cable on your remote controller. DJI still hasn't fixed the problem where you can inadvertently plug the charging cable in backwards and break off the internal connector on the remote. -Eyeball the thing when you get it and you'll see what I'm talking about. Then mark the correct orientation with your wife's (-or girlfriend's) fingernail polish on the plug. -Or just a dab of touch-up paint if you're macho. It'll save you a lot of grief!