I've started to realize, based on the fact that nearly any phone made within the last several years has enough processing power for most peoples' needs, at least within the current frame of reference for what we expect phones to do, isn't there becoming a time when certain phones may become collectible for a lot of people? Or, being that production numbers are usually so high, at least sought after or desired, if not actually scarce?
To illustrate what I'm talking about, I'm still loving my Galaxy Note Edge, going on three years since it's been released. After my old one got stolen, I went to great lengths to scrounge up another new one. (All the used ones I found for sale were crappily refurbished. Phones don't seem to come onto the used market in very good condition.) It's an oddball in that, AFAIK, it was the only "edge" phone from Samsung to only have the edge screen on one side of the phone. And in a way, it was even more interesting and radical than later edge phones. I've compared it side by side with later models with curves on both sides of the screen, and they actually don't wrap around the side of the phone to quite the degree that the screen on the Note Edge did. It also had a lot of weird stuff going on in the edge screen that I don't think ever got duplicated on later phones.
I wanted to get a waterproof phone to use when kayaking. Of course I didn't want to drop big money on a new phone, so I found an S4 Active. I'm a big fan of the fact that it's both waterproof and retains a removable back cover and swappable battery. I kind of thought the two of those things were mutually exclusive to one another. Then I realized that Samsung did do it with the S4 and S5 active, before they went all-in on phones with non-removable batteries.
A friend of mine at work used to swear by his old Samsung Alias phone. He didn't need a smartphone, and it had a really slick feature where each key on the keypad was its own little e-ink display. And the phone had a funky hinge where you could open it like a flip phone, and the keys would look like a normal phone, but open it like a clamshell, and the keys transformed into a qwerty keyboard for messaging. It was admittedly pretty cool and unique.