I've had Life Alert for a couple years but thankfully, never had to use it. I set it off twice accidentally when books fell on top of the thing they talk through!! Since then, I've put the books somewhere else! I think it's around $50 a month -- I use a credit card and don't pay too much attention, just pay the bill. I use the wrist band instead of the pendant as it gets in the way hanging around my neck.
Good luck!