The rest of that was,

> about 1/3 the price of the phone by the time you need it replaced

So that sounds plausible if iPhones can be purchased for $150-300 at the age you'd replace the battery. (Though that does strike me as a little low, still? Depending on how long the battery lasts...)

How is that logical? Why would you buy a phone for $150-300 that’s the same as the one you have, likely with ann old battery for that price, instead of replacing the battery for <$100.