its more like 470-650 for the i7 920 and x58.
there is such a huge variation on the price of x58 motherboards.
I had someone build me i7 rig cost over a grand. I am running Windows 7 64 bit. Only went to Windows 7 last week. So fare runs pritty. Buy good ram 1600 Mh or better if you can. Mines wimpy ram need to update it and a good heat sink also. Windows 7Â 64 bit is a ram hungry beast. 
Yes the cheapest and the second crappiest from MSI is about 180 and the EVGA classified MoBo is about 400$.
Where as AMD Dragon motherboards range from about 120 to 200 for a good board - excellent value.