where are u buying it from ?are u going to test the product yourself or are u paying in advance
there were different configurations for this keyboard - https://keychron.in/product/keychron-k8-wireless-mechanical-keyboard/
clarify regarding his specifications and so on then approach accordingly
For around 5k you can get Aula f75 or VGN a75 brand new. Not worth paying so much for used keyboard when there is lot of good options at this price point.