(1) Disclosure of cost of services. The psychologist shall not mislead or withhold from the client, a prospective client, or third party payor, information about the cost of his/her professional services. A psychologist may participate in bartering only if:

(a) It is not clinically contraindicated; and

(b) The bartering relationship is not exploitive.

(2) Reasonableness of fee. The psychologist shall not exploit the client or responsible payor by charging a fee that is excessive for the services performed or by entering into an exploitive bartering arrangement in lieu of a fee.