While I can't give you a direct answer, I can point you to a link for
a recipe for "Master Mix" (like bisquick) that includes powdered milk.
Havn't tried it myself yet. It should be quite a bit cheaper than
buying bisquick.

http://homesteadingtoday.com/vb/show...light=bisquick

BTW, there are tons of make-a-mix recipes in the Cooking and Craft
Forum on the Homesteading Today site.