Refurbished iPhones are a bargain - but then again that's really just an admission that while there *is* a market for long in the tooth iPhones this will only get you a modest percentage of the next shiny if you're a frequent upgrader.
I bought an iPhone 7 on eBay for $210.(for my younger brother, nah, can't be seen using iPhones in public ^_^)
How exactly is it different than an iPhone 8, other than the glass back and moving poop emoji?
And it wouldn't be any different than the iPhone X gang had Samsung not upped the ante and produced a curved-display phone.
TL;DR - Apple is no longer innovating, which justifies older flagship bargains!