At first, they'll be "performance" boards and will cost, I'd bet, about $170.
But they are not significantly (hardly at all) more expensive to make than regular SDRAM boards, so it shouldn't be too much!!
Eventually, I would expect baords to be under $100 (like the VIA Apollo boards are now).
The reason boards are so pricey now is because the i815 is so damned big. It has all the graphics and crap in it. Besides, Intel overcharges for their chipsets anyway. =-)
I think ALi and VIA will have cheaper solutions much quicker (because they have the motivation)
Eric