I saw the same thing at my local Costco store yesterday. The price was $2,989.99. There was a D600 + 24-85 VR on display that I was able to pick up and play with. Outwardly the quality of construction looks quite good although not quite as good as it is with my D700, but it costs a lot less than the D700. If I were shopping for my first full frame dslr I would be considering the D600 big time. I went from a D200 to a D700, and once you go from DX to FX it's hard to go back, especially if you operate in a lot of low light environments like I do in shooting gymnasium sports like volleyball and basketball. Being able to get great results when shooting at high ISOs in the range of 6,400 to 12,800 is hard to beat! I scarcely ever use my D200 any more.
Believe it or not, I'm still using a D80 that I bought over 6 years ago. Shots taken around ISO 1000 or above need work with noise reduction. Shooting at a clean ISO 6400 would be a complete dream.
I had already tried out the body at a camera store and like the size for my smaller hands. I'm sure I'll end up with a D600. The post was more about whether the Costco bundle seemed like a good deal. I may just get the body alone. Actually I already have that 70-300 so I'd have to sell it anyway if I got the Costco bundle. And I may still keep my 18-200 DX lens for travel.
I thought that I was in heaven when I got the D700 and found out that I could shoot at ISO 6,400 with minimal noise. Heaven got even better when I experimented and found that I could go up to ISO 12,800 and still get good results. Some noise is encountered when shooting at those high ISOs, but it's easily deal with. A few nights ago I shot a volleyball match at ISO 10,000. If you're interested you can view some photos that I shot during the contest. They're posted on the first page of the Sports Forum at a thread titled "College volleyball: Chico State bested by tough opponent."
I wouldn't consider buying the bundle either unless it contained the precise lenses I wanted. When I bought the D700 I got the body and ordered separately the walk-around zoom that I wanted to use with it.