Think well what are the reasons you want to do it. If it's to get girls (and you do have a GF) than its not worth it. If its because of low self-image, try hitting the gym or other stuff before going to such a thing.
It's neither girls nor a low self esteem due to my height. My problem is that my family and close friends are all huge, being below 180 is enough to get called a "dwarf" in my family, in a joking way, it doesn't feel good nontheless.
My height neurosis got to a point where I could probably be happy without LL, my fear though is that my neurosis comes back one day when I'm much older (I've just turned 20). So I've saved up a little over 32 000€ for an internal nail, but now that it got less important to me I don't feel good spending this much money on a surgery. So I'm kinda deciding weither an external lengthening might not be a better option since I don't want more than 4cm's anyways.