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.