(1) A chiropractor shall not enter into an agreement for, charge, or collect an illegal or clearly excessive fee.

(2) A fee is clearly excessive when, after a review of the facts, a chiropractor would be left with a definite and firm conviction that the fee is in excess of a reasonable fee. Factors to be considered as guides in determining the reasonableness of a fee include the following:

(a) The time, effort and skill required requisite to perform the chiropractic service properly;

(b) The fee customarily charged in the locality for similar chiropractic services;

(c) The experience, reputation, and ability of the chiropractor performing the services.

(3) A chiropractor shall not prescribe nor perform any services which are not reasonably necessary in consideration of the patient's condition and shall furnish an explanation of charges for chiropractic services upon request of the commission.