Yeah, I truly believe this is their business model. I paid about $350 for mine from NNG (which I was okay with), and felt that my chances of getting this immediately after release date was pretty high with them. (I got mine from NNG on 12/3.) I'm certain that if I had managed to snatch one up during their initial, lower-priced PO window for this, either I wouldn't get it till months later or I would never get it at all from them. I read reviews where lower-priced POs were later cancelled on NNG customers, and the item went back in stock and relisted at a much higher price on NNG's website.
Don't get me wrong--I'd still do business with them, but I'd have to be realistic with my expectations on their services based upon how much I paid for a particular item.