iOS Question Which old iPhone is the cheapest version, which operating system version is minimal, for B4i in 2020

[a6000000]

Which old iPhone is the cheapest version, which operating system version is minimal, for B4i in 2020

iPhone 4 ?

iPhone7 ?

 

[Biswajit]

I would recommend iphone 7

 

[Erel]

Check this: https://david-smith.org/iosversionstats/

I highly recommend to use a device that can run iOS 13+. iOS moves faster than Android as all recent devices are updated.