Thank you very much, bocephus. I replied to your message. I wouldn't expect anybody to pay right away though. First I will make an HD video of the unsealed box / phone (at the buyer's request).

If the buyer wants me to send the box sealed, then I'll make the video before payment. If the user wants me to test the phone, then I'll require payment first, and only if the phone is found to have any issue whatsoever I'll refund the payment right away. This all sounds logical, let me know if you don't agree.