Amazon.com (just add to your next book or cd order)- has 90x90 inch, 3 pound lightweights, for $399.
The best- http://cashmereblanketshop.com/All-Cashmere-Blanket.htm
Queen, 95x102, Brlin de Vian-Tiran pure Cashmere ('Kasmir') 300gm/meter is $2900.00. 'Mongol', 95x102, 300gm/meter, is $2400. A 'Natalia' 90x90, also 300gm/meter, but plain jane color and border, is $1100. One of these weighs almost 9 pounds, so not lightweight.
I found a Natalia at another site for $916- (http://www.bellacor.com/productdetail/486193.htm)