33. Fees are fair and reasonable if they are warranted by the circumstances and are in proportion to the services rendered. A medical imaging technologist, radiation oncology technologist or medical electrophysiology technologist shall bear in mind the following factors in particular in determining his fees:
(1) his experience;
(2) the time devoted to performing the professional services;
(3) the difficulty and scope of the services; and
(4) whether he was called on to perform unusual services or services requiring exceptional competence or speed.