Difficult to make comparisons in different countries (this is Australia). Was AUD$95.00 for me on both occasions, 7-day "Priority" turn around. Breakage occurred in August 2002 and November 2005.
Replacement of the lens release button is very straight forward, but that set me back $80.00 and again the camera was out of service for 7 days.
Both items are usually checked as routine when camera comes in for any other service as they are acknowledged weak points on an otherwise quite well fancied camera.
Neither the dial or the lens release button is a DIY repair task.