Many Polarizers have index marks on them. Buy two, hold one up to your eye and then set the Polarizer on the Camera to match the mark. If you have two that are not marked, hold them together and turn one until the image is completely black. They are oriented 90 degrees from each other. Mark each accordingly. You could but a cheap viewer, like a Sandmar, and attach the second filter onto it. This would be a lot less than $100!
I have a Kodak Series VI Polarizer with attached viewing filter. It screws into a Series VI retaining ring. The little polarizing viewing filter "orbits" the camera's filter, attached on a handle.