Wacker is a German company, that shop you linked is in Estonia, and you're in the northwest. Neither should you have to pay that much, or ship it that far!
Try to contact Wacker's North American HQ, which happens to be right around the corner from me:
3301 Sutton Road
Adrian, MI 49221-9335
I'm sure they can tell you who distributes or uses their products, and if you're lucky, they might even get you a sample.