Most original batteries will likely have significantly degraded capacity by now. Budget for a replacement if the seller hasn't already installed one.
A significant jump in performance and display quality for only slightly more (~). Is it worth buying a Oneplus 5?
Be aware of a known "jelly scrolling" effect on some units due to the display being mounted upside down by design. Top Alternatives
Found on platforms like eBay and Mercari , with prices often dipping below $90 for fair-condition units.