Gigabyte P55 UD4 - $199.99
Gigabyte P55 UD5 - $229.99
Gigabyte P55 UD6 - $269.99

MSI P55 GD-65 - $179.99
MSI P55 GD-80 - $249.99

Based on prices in Europe, it should be around those prices.

(Note: I didn't take the EU price and convert it, I compared the price in Euros of boards that are already out compared to pre-release prices in Europe. For example, an Asus Crosshair III AM3 board goes for 155 Euros in Europe, which is what the price of the UD4 will be. So if a Crosshair III goes for $199.99 here, then the UD4 will cost the same, etc)

Perkam