Has nothing at all to do with cost. I react violently to some unknown components of regular hair coloring. I have to get special dyes that are made for chemically sensitive people. Trust me, shit's damn near as expensive as a salon job.
That being said, I've been doing my hair since I was a teen, I'm good at it. Told you, I wanted to go into cosmetology once. Lots of shit you can learn if you know how to find a library, crack a book and/or surf the web.