it is about $25 I think, but the best way to know what is in your specific water for brewing:
I did the w-5 but I think you could get away with the w-6
the results look like this for me:
see post 39 for my water results (I am on a well).
Also, this thread is sort of dead - you may want to repost on the Syracuse grain buy #5 to see if anyone in your area has done this yet. I would say you are fine to mash unless you can't drink you water without plugging your nose
If you have a water softener you would won't to address the chorine, etc., with cambden. Some other guys on here have done that, but I ahven't since I don't have that issue.
My water is clsoest to the dublin style.