If you are that hard up, go 2 parts cornstarch and 1 part baking soda. Cheap!
Incidentally, I add a couple of drops of lavender oil to mine. (I make about 1/2 cup at a time and use a travel bottle to store) I use it when I need to refresh late in the day. An old baby’s sock makes a great powder puff.
Sounds like a good idea. Now where do I get an old baby?