(a) A reservation business may not charge its customers unfair or unreasonable prices. To insure compliance with this section, the Commissioner shall perform audits as provided in § 141.58. In performing those audits the Commissioner may inspect all original books, records, and other evidences of the cost of doing business. In addition, at least once a year the Commissioner shall cause to be made a survey of the prices of flour, sugar, fresh eggs, lard, coffee, ground beef, bread, cheese, fresh milk, canned fruit, and such other goods as the Commissioner deems appropriate in all stores licensed under these regulations and in a representative number of similar stores located in communities immediately adjoining the reservations. The results of the survey shall be posted publicly, sent to each licensed business, and made available to the appropriate agency of the tribal government. Copies of the survey shall be available at the office of the Area Director.

(b) If the Commissioner finds that a reservation business is charging higher prices, especially for basic consumer commodities, than those charged on the average based on the studies conducted under the provisions of paragraph (a) of this section, the Commissioner may order the business owner to show cause under the provisions of § 141.56 why an order should not be issued to reduce prices. If the Commissioner determines that the prices charged by the business are not economically justified, based on all of the information, then the Commissioner may order the business to reduce its price on all items determined to be priced too high to a reasonable price as determined by the Commissioner, but in no event to a lower price than the cost of the item increased by a reasonable mark-up.