I teach a course on use of Photopolymer Mask which is exactly what you are looking for. I currently have a class in Washington DC at Weisser glass on Dec 4and 5 . Cost is about half of what you were looking at.
Also, the material is less expensive by itself and the remaining materials and equipment for the entire process can be purchased for less than $50.
You can see examples on my website (see below) on the Gallery 1 page.
We are currently setting up our 2009 schedule and may have a class closer to you.