Most fire departments will also give them to you for free. My brother is a professional fire fighter and always has a box of them in the back of his truck to ha

Most fire departments will also give them to you for free. My brother is a professional fire fighter and always has a box of them in the back of his truck to hand out to people. They'll even do volunteer events where they'll come and inspect your house to make sure you have proper placement and they're not too old. At $60 each I might replace the 5 I have in my house, at $130 I don't think so.