the brilliant cut grinders website is actually called grindersforlife.com, they boast that their super strong allumin alloy will truly last a lifetime. However, it is conceivable that the grinder plates may eventually wear out after 25 years of hundreds of thousands of buds which is why they sell them individually just in case. In theory I suppose less parts mean less room for failure points, but if your grinder is modular even if a part does wear out its always easily replaceable.