You see how dark the one is above? For a basic purple shampoo, you’ll typically spend between $6 and $12. For a mid-range purple shampoo, you’ll typically spend between $13 and $20. Lower-tier purple shampoos might have a lighter shade, a smaller bottle, or poorer-quality ingredients. It makes a huge difference in a good way… Purple shampoo pointers… The purple shampoo bottle will tell you to apply it to wet hair in the shower for 10 minutes, but is to apply it to dry hair and leave it on for upwards of 15 minutes and THEN wash it out. Here’s a photo of one of my clients before and after she started using purple shampoo for the first time. You can find purple shampoo for anywhere from $6 to $50. A good purple shampoo will be dark purple, not light purple, and it shouldn’t be transparent. Even though purple shampoo isn’t a dye, but a neutralizer to get rid of the yellow in your hair, if you let your hair be exposed to its formula for too long, the only thing that’s going to happen is the violet pigments of the shampoo will leave a horrible blue or green tint in her hair depending on your hair color. That’s what you should look for.