When I was in school, getting new head shots was something of an ordeal - not only getting the photos, but also getting multiple copies at a reasonable price.
(By the way, I used to hate it when professors, or people like me would say, "when I was a student...." and here I am doing it!!)
In any case, even though this is a much easier procedure these days, I am amazed how many bad, or to put it more correctly, inaccurate head shots there are out there, even with managed artists.
While a good head shot won't get you hired, a bad one might keep you from getting an audition.
I don't think it's a risk worth taking.