Estimates include a basement, plus heating and air-conditioning, but not land or site development. A thousand windows ordered by a developer cost much less per window than a custom builder's order of 10. But that isn't necessarily so. It may depend on how good the architect is.
Architects have myriad solutions for controlling costs without reducing quality.
They can adjust layouts to make them easier to build, substitute less expensive but still beautiful materials and help to screen builders so bids are comparable. Dream House architect Dennis Wedlick keeps the price of his homes down by using products readily available from most lumberyards and by following standard construction methods. I still get my design, but when a builder looks at my plans, he's not afraid. He'll say, 'Oh, I know how that goes together. That makes all the difference between a price that's reasonable and one that's not.