Another way that I save money is by making my own shampoo. Not only does it save you money you know exactly what is going into what you're washing your hair.
1 gallon of water
1/2 cup of baking soda
1/4 castile soap
3 tsp of Xantham Gum
A bottle for foaming soap or a spray bottle
First, boil the water and add baking soda.
Turn off the heat after you've added the baking soda and let the water cool off.
Then add the Xantham Gum.