So far my phones tend to last until the screens break or the batteries give out. On one occasion I upgraded because a particular OS version level supports a la

So far my phones tend to last until the screens break or the batteries give out. On one occasion I upgraded because a particular OS version level supports a la carte app permissions. I'd be really surprised if an Apple phone would have been cheaper than a small handful of cheap phones over the span of 20 years. To be fair I could have bought used / refurb iPhones. And it looks like my plan offers a new iPhone SE for around $300 when all is said and done. Now had I been really smart, I should have invested the savings in Apple stock ;-) The Boots theory sounds clever, but of course would need to be supported by evidence.