What you should pay attention to is that
1. Carefully observe the bright spots or bad spots on the LCD.
2. Has the battery been packed and replaced with an assembled battery with rough workmanship?
3. Can you read the stick assigned to you? Is its capacity accurate?
4. Does the machine have any disassembly marks to prevent the refurbished machine?
In short, take a closer look and think.
If the price is much lower, something may have been switched.