about 2 years ago i bought a guitar and took group lessons for the first time. the lessons were good b/c the instructor personally shows you how to hold the guitar for your body type and exactly how to finger the chords.
$150 for 8 sessions was well worth it for me. i also bought a $10 dvd when i got the guitar. for someone who thinks they can pick up the handling and chord fingering if they just watch someone play, then a dvd might be the only investment you need. you can sit right in front of the tv and pause/rewind until you get it right.
all in all, the best way to learn is just practice more than you really want to. it takes dedication (and lots of sore fingers) to become even half-way decent.
you can get a decent acoustic fender guitar with a case, strap, tuner, and dvd for under $200 at guitar center. wish i knew about that before i spent twice that on mine.