I just dropped off my duvet at the dry cleaners for a wash. It costs £20 to wash a double! We wash it once a year. But really it's twice, once for the winter one, and again for the summer one. I don't used to look at the price of things, but now with DD, I'm beginning to get skint. 
How do you ladies wash your duvets? And how often? I just can't believe everyone pays £40 a year to wash a duvet! And probably double that when DD moves on from her grobags.