I was prescribed one after having a series of unknown allergic reactions. I would get new ones ever couple years (often keeping expired ones around) and with the changes in Health insurance over the years my payments have been going up. I am thinking about asking my doctor to just prescribe epinephrine and regular syringes. I've read a few articles saying some are doing that since its substantially cheaper (though not as convenient and doesn't last as long). My hope is that I never have to actually use it :-).