My sister is a very low-tech iPhone user. She has a 5 right now, but is running up against the 32 GB storage limit with music and photos.
I want to get her a used iPhone and am probably looking at an SE, 6, 6s, or 7.
What is the oldest model I should consider to balance price with future proofness.
I really like my SE.
I donât want to carry an iPad around in my pocket.
It still works well, isnât slow, etc. Battery life is good.
Edit: just checked Gazelle and theyâre less than $200.
If she is low tech, I would probably go for NOT the 7 as it was the first to drop the headphone jack. Itâll buy her a few more years before making the jump to bluetooth headphones which can always add an extra headache. (if she has AirPods or wants to buy them then ignore that as a concern).
I would avoid the 6 because of the issue with them bending. We had a lot of them deployed at the company I work for and that was a big issue for us. Coming from a 5, I think your other choices would all be fine. Other than price, the other factors to consider would be screen size (smaller on the SE), headphone jack missing on the 7 but has better water resistance. The touch Id button changed to haptic feedback on the 7 but I never had an issue with the real buttons. Obviously the 7 is faster, but I donât think that would be a factor.
Personally for me, I would pick the 6S for the larger screen and headphone jack.
I agree; I think a 6S may be the sweet spot unless the small size is paramount. Both my parents use a 6S (same CPU as the SE), and iOS 12 has breathed new life into them.
All of these options can have their batteries replaced, which is nice:
I have a 6S as my âtestâ iPhone (running non beta OSes, but thatâs me). Itâs a great phone, nice and slim, not too big, and fairly recent.
Iâm still on my 6 and itâs still good. If I finally upgrade at the end of this year the plan is to pass it on to my wife, ie we still expect it to have a few more years of use for her as a phone and email machine only, pretty much.
Confirmation bias: I found this article that agrees with me 
I was half-expecting to find youâd written it, too!
My wife would happily downgrade her phone if it didnât cost money to do so. Currently she has a cheap touchscreen phone, but finds the limited battery life (only 3-4 days) and its tendency to respond to accidental touches annoying. She would much prefer an even lighter phone with 7-10 days battery and buttons, that just makes phone calls.
Anything âsmartâ is done on her iPad, which is a much nicer experience for her.
Ordered a 6S from Gazelle. Thanks folks.