I'm about to perm my hair after a 4 month stretch, and I decided to use an entire line of products instead of mixing and matching. So I decided to use Paul Mitchell products. I went to Trade Secret, and they had the liter sizes 2/$25 and you get any styling product for $1, I got the ss serum. So I purchased $80 worth of products for $26. Also you can purchase any liter size product and receive a styling product for $1. Just wanted to share. 
