Buying used PSU

Hi, buying a use PSU I'm not sure if its perform a good performance. But I know Amazon is good, but if you have a budget for this its better to buy a new one PSU. Consider that if a use PSU one of the easy to burn parts is the capacitor because the capacitor have only a 150 temperature. If this is use probably you will not sure that this part is weak now. So after you use it might 3 months or 6 months this PSU will fail. Sometimes a bad PSU can also cause permanent failure of the other parts of computer. But I dont know AMazon how they check the stability of a use product before to sale it. If you buy this PSU be sure that this PSU wattage is enough for the system of your computer.