What are the costs of an audit?   The ROBERT THOMAS Group can be engaged for a fixed fee, a per diem fee, an hourly fee, or a contingency fee. The contingency fee method is most popular since RTG earns only a percentage of the money we save the client, thereby minimizing the client's risk. Some of our clients prefer a hybrid approach that varies by size or by geographic location of the premises. After we discuss your specific needs and help formulate your desired audit strategy, we will be happy to provide you with a firm price quotation.