I used to teach for a while.
$15 per half hour for beginners, $25 for intermediate or advanced.
The thing that drove me to finally give it up was that I wasn't cynical enough.
We would do the lesson. I would give them homework.
They would come back the next time having not done the homework.
Eventually I got to the point where I couldn't take the money for giving them the same lesson again.
I was trying to give them the building blocks of becoming a musician, not just being able to play a few tunes, but to really understand how music works.
It will be tough when they tell you that they want ot play really well, but you then discover that they're not willing to do the work to be able to play really well. If their goal is to play a few Beatles tunes around a campfire, then it's really easy to accept that - it's their goal that's important, not what you think their goal should be.
If you're okay with the idea that you will teach them how to play a few [insert name of flavor of the month here] tunes, then you'll be okay.
Beginner = How to tune, the notes of the strings, some basic chords (E, A, D, G, C, Amin, Emin etc.) and some strumming patterns.
The next two are difficult to define, as people's goals are so varied. e.g. Knowing what a Minor 6 chord is and how you use it is not going to be as important to a guy who wants to play like Ry Cooder as it is to a guy who wants to play like Django.
That's why I charged the same for both categories.
So, with that caveat, and generally speaking:
Intermediate = Can play the above mentioned chords and 'F' and 'Bb' smoothly below and above the fifth fret, and has some understanding of soloing, even if it is 'licks off of records' strung together with no understanding of why they sound like they do.
Advanced = Has an understanding of scales and arpeggios (although may not know what they are called or why they sound 'right' together) and how they are used in making music, how they relate to each other. Knows what a major seven chord is, possibly how to play different inversions - e.g. 3rd in the bass, 7th in the bass, etc.
Be careful what you wish for . . .
foo