Appraisers will charge different fees depending on their expertise, the difficulty of the assignment, etc. No single fee structure exists nor would it be fair to suggest what an appraiser might charge. Some charge by the item’s major diamond size (i.e., more for a larger center diamond and less for smaller diamonds). Other appraisers charge a flat fee per item. And others may charge by the hour. In any case, a fee that is based on a percentage of the appraised item’s value is considered unethical in the appraisal industry. In this case, an incentive exists to inflate the value for a higher fee. If an appraiser quotes price as a percentage fee this would indicate that he or she does not adhere to industry standards.
The most expensive appraiser is not necessarily the best, nor is the least expensive necessarily the worst. However, with appraisals, you generally get what you pay for. The short “one-line” appraisal with a value is not nearly enough information to describe adequately an expensive engagement ring.