Many things that are sold used are in poor condition and have been misused. You are frequently inheriting someone else’s problem and have no way to know if the device is in working order or safe. You might end up having to replace the batteries or tires and it can be hard to spot a scooter that has been misused.
You also run into a lot of no-name generic scooters on places like EBay. These are mass produced in a place like China or India and are frequently not held to the same high standard as those made by reputable companies like Pride or Golden.
It is far better to purchase a mobility scooter new from a reputable dealer. This way you are guaranteed that the device is in perfect working order and will provide years of reliable service. Golden and Pride both offer very comprehensive warranties on their new scooters, so if something does not function properly, you can have it quickly repaired at no cost to you.
You are taking a very large risk when you purchase a mobility scooter used and when you factor in the cost of repairs, it often ends up costing just as much if not more than a mobility scooter that was purchased new. Saving a little money is never worth risking your safety or that of a loved one and this is what you do when you buy a used mobility scooter.