Buying iPhone 15 PM

Hey guys I recently decided to upgrade to a newer iPhone. I liked to 16 series but I saw the new or slightly used 15 PM on the marketplace for 700 or 800 CAD (1 tb model). The seller's sometimes mention that we can meet in the apple store to show that the device is genuine How can I trust? Or should I play safe and get the newest one? Check this one for example: