Same here.. completely self taught except for maybe a few lessons here and there when I needed a kick in the pants to move to the next level.
I didn't have internet access to videos then though, so I don't know what the answer is now.
I guess it depends on how good the teacher is and how long you're prepared to keep at it.
With a teacher you might get a more structured approach but in my experience it's a very slow process (one lesson per week at $15 - $25 a lesson ain't cheap either).
Plus, you only get 1/2 an hour and for the rest of the week you're on your own anyways so really, you're mostly self taught even with a teacher, except you have somebody looking over your shoulder to guide you.
I also found that teacher based lessons were always very theory oriented.
Which is great if that's what you want, but if you just want to play in a rock band, you might not be interested in learning jazz theory or how to read music.