Yep that's what may make the Phenom II attractive. You can run it in a 100usd 790GX mobo with 2 x 2Gb 45usd ram. X58 mobos are around 300usd and up. The cheapest DDR3 1066 2 x 2Gb ram kit I've seen is 94usd.
Honestly a 160usd Phenom 9950 @ 3.1GHz will support most all graphics cards well. You could get that, some ram and a mobo for the price of a single X58 motherboard. You could put that extra cash towards an HD 4870 1Gb. They're down to 239usd currently.
Of course the best price vs performance quad out is the Q6600 G0 for 190usd. It will do 3.6-3.8GHz in most cases. I've tested Tri-SLi extensively with an i7 920 @ 3.2GHz and 3.96GHz. @ 1280x with no filtering I lose 5-8FPS in the 60-80FPS range @ 3.2GHz. At the res I actually play, 1920x, I lose even less. My point is, you don't need a 4.0GHz i7 920 for a pure gaming ring even when running something like well overclocked GTX 260 Tri-SLi. The i7 920 @ 4.0GHz is far better than the Q6600 @ 3.6-3.8GHz, and not to the tune of +100usd.
Thats why most people are comparing it to C2Q then i7, My setup is gonna be around the same for a decent phenom 2 setup, Can not wait to see what stomps what.
Also a Decent 790gx boards run 120+ btw . You can find cheaper x58 boards for under 250, All you sacrifice is either 3 dim slots or some cool looking coolers. i7 is very affordable if you want to make it, but you gotta remember its high end so of course its gonna cost a pretty penny.
Why get a 9950 over a Q6600? Its around the same price for both (790gx, 4gb, cpu vs p45, 4gb, cpu).
To me most/majority of the people that have moved to i7, do it either for future-proffing, Finally made the upgrade from their duals, or just wanted to. An i7 rig is worth every penny imo.
Like i said countless times, the phenom 2 is gonna be a decent chip, but im more interested to see the am3 setups.