Why buy an iPhone at all? Apart from a better touch interface than almost all others in the first year, they have always been overpriced, poor performance, hyped and at least since iPhone 4 or 5 no advantage over the cheaper, better performance competition.
I use a Sony Ericsson Xperia Z1 bought S/H for €50. Had it for ages now.
It has a real phone jack, micro USB, micro SDHC (32G card plugged in), Micro HDMI, nice FM radio and good enough camera.
I have for comparison a 32G iPhone 5 I was given, much inferior. I used it a few days and went back to the far better Z1
The new iPhone 7 sounds dreadful for nearly £600! No earphone socket, no SD card slot, worse battery life than iPhone 6 (which was already poor).
Loads of far cheaper far better phones out there.
The "eco system" argument is bogus. A Mac user can use any brand of phone and MacOS != iOS and also any OS Laptop can use an iPhone (I was surprised I can connect iPhone 5 to Linux and browse / read/write all the files, no iTunes installed, I doubt that works on Windows or Mac).