You can always buy the book (hardcover or kindle(pdf)) first. It's called Beyond stuttering by Dave Mcquire. I bought the PDF version on Amazon recently and reading it through the Kindle app. Try it out before spending money on a course. But this takes hard work and at least 6 months of dedication before making a decision to quit or use the techniques for the rest of your life. You need to be brave and get out of your comfort zone. All the best.