I have to disagree with you. Yes, you can guy ATi's highest single GPU card for under $200. However, that is simply because ATi can't sell their highest end single GPU card for any more than that. If they did it wouldn't sell. Yes, nVidia is releasing very high end cards, and charging a premium for them. But ATi would be doing the exact same thing IF they could, their highest margin cards are the high end cards. They make the most profit on the super high end cards. Just because you can buy ATi's best single GPU card available for under $200 doesn't mean anything. You can buy cards from nVidia that are equal, or even better in performance for under $200. ATi's marketing isn't any better, they just can't managed to make a single GPU card that can outperform nVidia's so they have to sell the cheap, the problem is nVidia has cards that are just as cheap and better.
The G92 and G80 are wonderfully designed cores, they seem to be doing the job against R600 just fine. The problem with ATi's design is that it is incredibly hard to add that brute force that they need so dearly. The choice by nVidia to unlock the shader clock speeds from the core clock speed was probably the best move possible. Instead of just increasing the shader count to boost shader performance, they raised their shader's clock speed. The problem ATi has is that it is hard to get so many shaders stable at any kind of high clock speeds and why we have nVidia cards with less than half the shaders of ATi cards destroying ATi cards in performance. That is why nVidia has a card with 64 Shaders outperforming ATi's cards with 320.
I don't see how anyone can say that ATi's design is more logical than nVidia's when nVidia is releasing mid-range cards with 64 shaders that are beating ATi's best offerings with 320.
And that takes me back to the "marketing" issue. Yes, the 3870 can be had for under $200. That is all good, but the 9600GT is overall 4% faster(it is 3% faster than even the 2900XT) AND it can be had for ~$25 less than the 3870. Personally, I think nVidia releasing a cheaper mid-range card that outperforms your competitors best offering is damn good marketting.
I never said 1 GPU is greater than 2. However, I was comparing GPU to GPU, apples to apples if I need to break it down into simplier terms for you. NVidia's dual GPU card is on the way, and when that comes we can compare 2 GPUs to 2 GPUs. My argument was about who is technologically ahead, and part of that argument is comparing apples to apples and seeing who's technology is in the lead. Yes, performance wise ATi is in the lead, but my argument wasn't about performance leads, it was about technology. My point was that if ATi can't produce a GPU that can outperform nVidia's GPU, then how are they in the lead technologically. Because, as we already see, if you take a weaker GPU and stick two of them together on a single card, then the other side is going to exactly the same thing with their stronger GPUs and end up with a stronger card. To get a fair guage one who is in the lead technolgoy wise you need to look at Apples to Apples, or in this case GPU to GPU, not GPU to multiple GPUs.
Now to correct some of your misinformation about the 3870x2:
Personally, I don't even know anyone that owns a monitor that runs at that resolution, and if I did, I doubt they would be using a single 3870x2 to power it becuase they would probably be rich enough to have more than that. However, you can make any card look good if you just look at one single aspect. However, I prefer to look at overall performance, at multiple resolutions, on multiple different benchmarks. Lets take a look shall we:
Some interesting things there. When you look at overall performance, a very different story is told compared to your single narrow bit of information. You see a story where the 3870x2 is only 5% faster than the 8800GTX, and only 8% faster than the 8800GTS 512MB. Not exactly worth the $180+ price premium IMO.