Sorry, but not a good deal. As I recently posted in a thread from 1SaleADay, but it applies here as well:
Here is your list of authorized dealers, or just type "Nikon authorized dealers" into google without the quotes, and click on the PDF that comes up:
I can tell you for a fact that Nikon USA doesn't sell the camera body only, only with 18-55mm lens, so this is assuredly gray market. No Nikon USA repair is a no go, skip this.
Those lenses and other accessories have value, however, even not counting what I said about warranty above. I am guessing that he got the 18-55mm VR and 55-200mm VR lenses, which is about $300 in gear, plus the Wu-1a wi-fi adapter is another $60. Add the cost of any bags, tripod, and/or card, and your brother-in-law may have come out more ahead than you expect.
I do agree about getting some third party batteries. The Nikon D3x00 and D5x00 cameras have tiny little batteries, which is quite annoying, especially in light of the Nikon V1, which uses the same huge battery as the D7000!
The D3x00 series cameras, as I mentioned above when I hashed out the no-warranty argument, are not sold in the United States without an 18-55mm lens, but the D5100 is. I have two thoughts about buying the 18-55mm lens:
-First, you can always sell it on Craigslist and get a quick $80-$100, so it isn't that big of a deal.
-Second, why don't you want the 18-55mm? I really recommend it for first-time DSLR buyers. The image quality is just as good as you'd get at the top of the lineup, the only thing that you're giving up is build quality and lens speed. Plus, in the future when you step up to a higher-grade lens, you will understand why it's better, since you've moved up. It's the same thing as teaching someone to drive on a Ferrari; they're never going to understand WHY a Ferrari is good, because they haven't experienced anything any different. Definitely consider starting slow, and working your way up. Also, you might find some bonuses to the lens. You may want to throw it on your camera when you want a small, light, inconspicuous kit that still has respectable image quality. Or, like me, you may run into a situation where you don't want to risk damaging your big nice lens, so you put your 18-55mm on the camera when you want to not be held back worrying about your gear. For example, I used my camera one time to shoot a water balloon fight, so I put a plastic bag around my camera, stuck the 18-55mm through a hole, and went shooting with impunity. It worked excellent, and the 18-55mm even still works normal to this day.