Assalamu Alaikum. The mobile is completely okay. There are no problems of any kind. It is a perfectly running mobile. The back part has been changed. Apart from that, the display, battery, and everything else are original. A charger will be provided with it, no box. You can sit and check the mobile for as long as you want, no problem.
The price can be slightly reduced, but don't waste your time by quoting ridiculous prices.