I've never paid anyone to do a string change. I've only for paid one set up in the 28 years I've been playing. Paid $70 + strings (in 91) for the store's "Tech" to set up my guitar. That set up was complete garbage! Then I paid $35 for a book (again, early 90's) on how to do set ups & basic repairs. I do my set ups & my bass player's who prefers mine. I'm always amazed when there's a person who depends on a tool to accomplish their goals but won't take time to understand how it works or how to know when it isn't working properly.