The Hondles in Enumclaw had a Guernsey for sale a month or two ago. I don't know if they sold her yet, but you should try there first. She is 5 years old, very gentle, and is great for hand milking. $700. 360-802-4939 or 206-255-3288
Where do you live? I'm on Vashon. Do you already have cows, or are you just getting started?
We live on the olympic penninsula (washington state) way out on the west end about 14 miles from the Big Watery Place (misconceptually called the Pacific Ocean, as it's anything but quiet and pacific in nature).
My wife's father was a vetrinarian so she had some contact with animals. Her mother, for a long time, had a guernsey milk cow. I was raised on a ranch and have had and milked cows most all of my growing up years. I have a fondness for gurnseys or jersey/guerensey cross breeds.
We just got married last fall and so we are just starting out. We are also trying to find a supplier of pullets (not chicks) in the area but I don't seem to find any and that seems strange for such a back-in-the-woods place as we live.
The Hondles have already sold their cow, so it's back to the search.