I know a guy that is a master kydex holster maker. He buys his kydex in bulk out of the Hillsboro area. He does crazy good work. I have about 10 of his holsters and mag pouches. He said that he got his start when he could not find a holster that concealed well and yet was fast and reliable. I think that he lives in Silverton, but he is like a ghost. In other words...you have to know how to get in touch with him.
Now I'm interested...
A quick google revealed these folks, who sell it by the sheet. A 12x24 sheet of black runs about $17.05
A click on the "About Us" link shows that they have a distributor in Portland (and in Kent, Washington as well).
Looks like fun stuff for all sorts of hobby applications.