i've been playing 7 years, never had a lesson, and I'm happy about where I am.
Looking back, i would be much farther now had i had a teacher than i am, but at the same teachers can hold you back unless they are a good teacher, like strummin said.
frankly, if you have experience with sax, you can probably go without the lessons.
There are enough resources on the web, and good books for you to learn what you need.
Here some reccomendations:
*Fretboard Logic SE (Volume 1 and 2 combined)
*Fretboard Logic III (get after you know 90% of stuff in SE volume)
*Get a good music theory textbook, with worksheets and stuff, and do it like your in school (or take a class) Work through basic and advanced music theory, then get into jazz comp, harmony, counterpoint and composition.
*Learn Every note on the fretboard (BT Absolute Fretboard trainer for a good program for that)
*make flashcards as you go, you gotta learn alot of stuff: all your intervals chords, scales, arpeggios, triads, inversions, modes, chord progressions, etc etc.. and you should learn how to to recognize these written in tab and sheet music, as well as knowing multiple ways to play each one on the guitar in multiple positions
*Do some ear training, search google or bt and find yourself some good ear training software (i use auralia, but the cheap shareware versions are pretty good too). Start by learning how to regognize open strings, which string a note is played on, then learn how to recognize chord types, intervals, and scale eypes by ear.
*Develop a good practice routine.. do it daily, thorougly and methodically, if you can.
*Do yoga, stretching and/or meditation in order to let the creative juices flow, and minimize stress and tension in your body.
*EXPERIMENT.. theres a TON of theory and forms and all this and that, but sometimes you just gotta look at the guitar like you dont know anything and just start playin stuff that siounds fun.. try new things, and dont stick to convention (just learn it)
*learn COMPLETE songs beginning to end, then dissect then to see if you can understand whats going on in them
okay theres some ideas to start with (or too many) dont get overwhelmed, just have fun.. ultimately the key is to practice, frequent proper practicew ill usually keep you out of a rut, and help move you along quickly.
most guitar/music books suck.. the few that i've listed, and maybe a handful of otehrs are good, but overall guitar books suck, as do alot of teachers.. but if you can get the right books, and a good teacher, do it.
ill post some good links later for ya, but i gotta get back to work
"I reject your reality, and submit my own"