Don't just look at the rating for those places with low reviews... actually read the reviews. If a few of those don't completely scare you away from "too good to be true" prices, then I have a bridge I'd like to sell to you.
Read the reviews for Best Price Camera
here and you should get a decent idea of how they can offer such low prices:
a) they take apart the packaging that the camera is in and sell *only* the camera. When you want all those important things, expect to pay an arm and a leg - end cost is more than from a reliable retailer.
b) if you DON'T want all those important things, your camera is suddenly on back-order
c) Warranty? Of course. Well, until you actually need warranty work done on the camera.
d) In at least one case of warranty work, camera was kept by Nikon (or Canon) - it was a stolen camera
There's a reason it's called "too good to be true."