49. Fees are fair and reasonable if they are warranted by the circumstances and proportionate to the services provided. A denturologist should take the following factors into account when determining his fees:(1) the time spent in providing the professional service;
(2) the complexity and extent of the service;
(3) the performance of unusual services or of services requiring exceptional competence or dispatch; and
(4) the cost to the denturologist of the products or materials necessary for providing his professional services.