Just in case you missed the little article in the Wall Street Journal.
This confirmed everything I THOUGHT, but now I have some evidence for my assumptions. In honor of the article, I wore the cashmere V-neck my mother bought at Harrods in London about 30 years ago. It was 100 pounds when the pound was par with the U.S. dollar (an event never repeated, at a time when I was too poor to go anywhere). Thick, made in Scotland. My parents were ecstatic at the price and my father was thrilled to be interviewed on the subject of how far American dollars were going in England. He was very loquacious and so was sad that his lengthy analysis was reduced to 1 second of radio time: "A cashmere sweater for $100!!"
By some weird harmonic convergence, I bought an old Hermes cashmere sweater at Goodwill (when what I want is a SCARF! Hear that, Thrift Store gods!!!???). It is the thickest cashmere I ever felt. I can hardly imagine wearing it indoors. I need to find this to test out my new cashmere knowledge, but I think Miss Em spirited it away.
The best place to feel nice cashmere is in vintage shops. No comparison with most of what you find today. Many bloggers feel that Lands End offers the best price/value ratio for cashmere nowadays. I tend to agree. Some of the cashmere at thrifts is so poor quality (and the bad stuff gets worse with age) that I won't even spend $3.00 on a sweater.
I guess if you want to test the best of the best with your hand, you could check out Hermes. I would be too intimidated myself.