Depending on style, amenities and finishes the costs can vary widely from roughly $200 to $450 a sq. ft. If you go the modular route, the costs can decrease dramatically. Some of the other variables might be needed site work, utilities including water and electric etc.
Look at the newer construction in the area, find homes you like and go to Town Hall to see who built them. That way to can deal with folks whose work you like and who have built in the area.