Because like all computers, there will arise overheating issues over time regardless how much you take care of the item. Used consoles, laptops, PCs are usually louder than brand new as the fans need to work harder to keep the unit cool. The only good used console is one that has not been used excessively or one that has had the fans and thermal paste replaced before damage is done to the cpu/gpu. Basically you are always safer buying brand new. 1 year warranty is good though.
Why spend 25% more? If it has a year warranty I'd be ok with this
still more expensive than the game cockup from 2 years ago. That was for a new one too. Would spend the 40 more for new to be honest.