How does the cost of a 2 story 3,000 sf Timber Frame home (with Structural Insulated wall and roof panels) compare with a conventional stick-built frame home?

The conventional wisdom is that timberframing carries a 15% to 25% premium over a stick built home. Part is the timberframe and part is that someone interested enough to go with a quality timberframe home will also probably spend more for quality fittings in the rest of the house.