Although silk filled duvet is expensive, they cost many times more than the cotton sheets you purchase from a discount store nearby, you will know they deserve the cost.
Cotton sheets may look like they are more serviceable. But they get quite uncomfortable when the weather is hot. Also, they cool off when it is cold. King silk sheets do the opposite. Silk is cool to the touch in summers. In the winters, silk fits warmly around your body thus preserving your body heat and keeping you warm. So, silk can keep you comfortable in all seasons.
You will find it is really a nice try if you keep any eye out of the king silk comforter.