Is it used or new? If it is a "gray market" lens (imported by a non-Canon business) it will not carry the Canon warranty, it is pretty unlikely for a new lens to malfunction. Some non-Canon sellers also offer a warranty good at other repair centers. Some people pay the extra for the reassurance of having the Canon warranty. Others are happy saving money and most never have a problem. So.... you pay your money and you take your chances. Also consider KEH photovideo - they are a very reputable seller of used equipment, which will have some warranty. Whatever, this is a fantastic "walk-around" lens!