Another student, Lee Ji-soo, 23, has started using her old iPhone 6 as a secondary phone. "Among my peers, older iPhones are actually more popular than the latest ones," she said. "The colors in ...

But just don’t think any old iPhone will cut it. Much like video games and VHS tapes, the older iPhone models that are raking in the big bucks at the highest prices are the ones that are factory ...