. Grading, condition or other attributes of any lot may have a material effect on its value, and the opinion of others, including third-party grading services may differ with that of BKA. BKA shall not be bound by any prior or subsequent opinion, determination or certification by any grading service. Bidder specifically waives any claim to right of return of any item because of the opinion, determination, or certification, or lack thereof, by any grading service