I bought an Iphone 14 from a car boot sale early this year.
The girl selling it looked dumb.
She showed my it, said it has a cracked screen, but I noticed it wasn't,... just the protective screen, also she said it didn't charge from the charge port.
Had reasonable battery charge on it, I made sure it was not account locked and got her to wipe it (used my SIM for connection) as it turned out it was the same network.
As it would charge inductively...I thought, what the hell, take a punt...she is either genuinely dim or a bloody good actress, hiding a major fault, perhaps!
The charge port was full of fluff and all it needed was a clean, the screen was intact and as a bonus it was not network locked...which she didn't know!
I paid £25 for it....she wanted £50 initially.
Sold it three days later on face-book...for £300. The chap said he is sending it to his family in Uganda
Result
