The better the reputation, the higher the fee
In general, there is a positive correlation between reputations and fees. The better the reputation, the better the chances that the teacher is worth his or her salt.
You can check the reputation of a teacher by searching through online review sites. I would suggest one thing: Pay no attention to short, quickly written reviews that are five stars because they don't really matter. Very few people will give a guitar teacher they worked with previously a bad review. Instead, my suggestion is to look for well-written reviews that are greater than three paragraphs in length. These are the reviews that prove reputations, and they are likely the ones that the teacher didn't ask for.
So, how much should I pay for lessons?
My aim is for this blog entry to be useful fifty years from now, no matter where you live. Let be honest: The average cost of living varies from locale-to-locale and from age to age. Any discussion about the current average rate of guitar lessons is defeated before it begins because of geographical differences as well as inflation over time.
That said, you can expect that where people teach often dictates both their reputation and their rate for lessons. People who teach at guitar shops charge very little for their services likely because they are new and are trying to build their reputations as a teacher. Guitar teachers who teach at dedicated schools for guitar probably charge the middle-of-the-road amount because they are riding on the reputations of the school that employs them. The solo operators who have their own dedicated space for teaching are the ones who charge the most and are most protective of their reputations. Which teacher is going to work best for you?
If you want to find a great teacher that's incredibly inspiring to work with, work with a teacher who has his or her own dedicated space to teach in. This person is most likely to have a great reputation, knows the value of a good location, a beautiful space, and probably has great systems to serve you, too. True, you will be paying more money per hour, but it's necessary for finding the quickest shortcut to learning guitar.